APPROACH AND METHODOLOGY OF A BUILDING CONSTRUCTION

APPROACH AND METHODOLOGY

In this section, we describe the technical approach and methodology, work plan of the technical components of the assignment, “Development of Commercial building on the Land of “99 Karim Chamber” at Motijheel under BJMC through share Basis”. In addition, we describe the structure and composition of our team assembled to meet this assignment’s objectives.

Methodology

Technical Approach and Methodology:

In this sub section we explain our understanding of the objectives of the assignment and methodology for carrying out the activities and obtaining the expected outputs within the overarching objective of this assignment: to develop a commercial building on the land of 99 Karim Chamber at Motijeel under BJMC. We reproduce each Objective given in the IFB below, and give our response directly beneath each one:

PART-3(A) :      CONSTRUCTION

Section 3(A).I   : CIVIL WORKS

Section 3(A).II  : PLUMBING AND FIRE PROTECTION WORKS

Section 3(A).II  : ELECTRICAL WORKS          

INTERNAL ELECTRIFICATION

SUB-STATION

Section 3(A).I   : CIVIL WORKS

1          GENERAL

This specification has been prepared with all possible care and diligence and every effort has been made to cover all types of materials and items of works necessary to complete the Project in all respect.

            All workmanship and materials to be used in the Works shall be of the best quality of their respective kinds as specified herein. All materials used in the works shall be new and obtained from the sources and suppliers approved by the Engineer. Materials shall comply strictly with the requirements prescribed hereinafter or, where such requirements are not specified in this specification, the latest issues of the relevant Technical Standard shall be followed. All test of materials shall be done from the laboratory/(ies) designated by the Engineer. The accuracy and sufficiency of information furnished in this specification is not guaranteed. It is the responsibility of the Contractor to clear any confusion or ambiguity in this specification well ahead of submission of tender.

2 MATERIALS

The Codes and standards specified as per IFB clause 6.5 that comply with the latest edition of the relevant code.  All materials, testing and execution shall be in conformity with these codes and standards unless otherwise stated in these specifications. Standard, Brand and other specification will be fixed as per agreement of both parties.

3 TEMS OF WORKS

3.1 MOBILIZATION AND PREPARATION OF SITE

3.1.1 Construction Requirement

Before setting out the new work and commencing foundation work the site must be cleared off of all those described above. On clearance of site it should be roughly leveled as required.

The trees shall be cut and their roots totally up-rooted as directed by the Engineer’s Representative. No tree should be cut unless it is absolutely unavoidable. All serviceable materials obtained from the clearing will be property of the competent authority as determined by the Engineer. Salvaged material may be handed over by the Contractor to the local authority on instruction from the Employer.

3.2 DISMANTLING & REMOVAL OF EXISTING STRUCTURES

3.2.1     Construction Requirement

Before commencement of removal/dismantling work, the structure or parts thereof shall be properly earmarked and necessary arrangement for stabilization of the adjoining structures shall be ensured by means of adequate shoring, shuttering, propping and strutting. The dismantling work shall not commence until the arrangement of safety of the adjoining structure has been insured by the Contractor, inspected and approved by the Engineer.

The contractor shall be solely responsible for any damage to the portion of structure which were not intended to be dismantled and make good the damages, if any, at his own cost.

The contractor shall comply with all safety regulations and shall furnish, erect and maintain suitable barricades and warning signs and take such other measures as necessary to prevent personal injury or property damage, all these barricades, warning signs shall comply with the by-laws, regulations and provisions of BNBC 93 and shall be to the satisfaction of Employer, Consultant and Local Authorities concerned.

This item of work also include cleaning and sorting out of the salvaged materials in a usable conditions, transporting and storing neatly for use/disposal as directed by the Engineer’s Representative. The items of dismantling works of different structures in foundation also include all excavation, bailing out water by pumping, drainage, bracing, shoring, etc. as found necessary and their subsequent removal and satisfactory disposal of all materials obtained from such excavations and backfilling to the level of original ground where required. The contractor shall keep adequate records of all dimensional measurements of the structures and all other information relating to them as revealed and obtained during their work and have such measurements and information duly endorsed by the Engineer’s Representative at site. The work shall not start unless full measurement is recorded by the Engineers Representative. In some special cases, however, the recording may be done after dismantling.

The salvaged materials before or after dismantling shall be immediately measured and recorded in presence of Engineer’s Representative and shall be in the custody or the Contractor until instructed to be disposed off as per instruction of Employer/Engineer. Any loss of any dismantled material shall be recovered from the Contractor’s bill at the recovery rate.

3.3 SITE OFFICE FACILITIES FOR THE ENGINEER

3.3.1     Description

The Contractor shall provide and maintain site office facilities during the construction period for Construction Management Unit of Employer and Consultant. The particulars of the site office shall be as below:

The floor area of the office shall be 60sqm minimum.

This office shall be protected against weather, dust, insects, noise and other nuisance to the satisfaction of the engineer.

The office shall be located in a position approved by the Engineer.

The office shall be divided into following rooms by walls with connecting doors:

One room of about 12sqm for Senior Engineer with one toilet.

Two rooms of about 15sqm each, one for the supporting staff and other for site meeting (with toilet).

One kitchenette of approximately 6sqm with gas facility.

Rest space shall be used or veranda.

The Contractor shall provide six office tables, two secretariat table, two cabinet and 12 chairs all of a design, standard and finish approved by the Engineer. The crockeries, tea sets, glass sets, door & window curtain shall have to be provided. The contractor shall provide one table and 12 chairs for conducting meetings at site.

Necessary cleaning, washing, removing of dust of rooms and toilets shall be done by the Contractor by engaging his own personnel.

The Contractor shall provide lighting and ceiling fans to the satisfaction of the engineer and the toilets shall be with mosaic, water basin, shower, one high commode, and one pan. The required number of electric bulb, ceiling fans, calling bells and electric power points etc. shall be provided.

There should be one telephone connection with independent telephone number.

Two numbers mobile telephone, one for Consultant and other for Employer’s, Project Manager.

3.4 EARTH WORK IN EXCAVATION

3.4.1     Construction Requirements

Before any excavation commences, the reference bench marks need to be carefully fixed on the ground at some suitable place by putting 16mm M.S. bar protecting it by 450 mm x 600mm concrete covering around it. The bar top should be the reduced level of benchmark. Bar top should be projected 2cm above the concrete top surface. The Contractor shall take necessary measure and protect the vertical shoring in such a way that the entire excavation (including the protective measures) strictly remains with the shore protection line. If any encroachment is done or any damages occur to any neighboring building & plots or to RAJUK lands, the Contractor shall be solely responsible for such damages and shall be bound to pay all compensation claimed by the owners of these lands.

The excavated earth excepting those required for back filling will be disposed by the Contractor and he will carry it away from the site to a safe place to be arranged by him (Contractor). The site should be kept clean and no earth should be deposited in or near the site.

The depth of excavation will be as shown in the plans and as per direction of the Engineer. The Contractor will keep the excavated level in such a working condition that it will be possible for him to erect all equipment during the excavation work and remove them after the excavation of the earth is complete.

Contractor should fill excess excavated level if any, to the design level by 1:3:6 concrete to the satisfaction of the Engineer without any extra cost.

3.5 EARTH FILLING

3.5.1     Construction Requirements

Silty Sand or other approved materials, free from large lumps, organic or other extraneous materials, shall be used for fill. Materials from excavation on the sites may be used as ordinary fill if it is approved.

The fill materials shall be deposited and spread in successive thin uniform horizontal layers of about 150mm thick and compacted by use of mechanical or other approved devices to 98% in standard Proctor in road and pavement sub-base and 95% for other area.

Tests will have to be carried out at Engineer’s laboratory to ascertain the nature of the fill material and the degree of compaction obtained for the filled material for which samples have to be taken and transported by the contractor at his expense and as directed by the Engineer.

3.6 BRICK FLAT SOLING (BFS)

3.6.1     Materials

Bricks shall comply with requirements of First Class bricks unless otherwise required by the Engineer. The blinding sand will have a minimum fineness modulus of 1.00 and shall be clean, and free of any organic matters.

3.6.2     Construction Requirements

The bed for BFS shall be prepared level and compacted, dewatered and cleared of all loose materials.

Bricks shall be laid flat in surface-to-surface contact with adjoining bricks and their joints shall be filled with sand. The sand shall be brushed in until the joints are filled. Flushing in of sand with water will not be done unless permitted. Bricks shall not be laid on the floor or foundation bed until the floor or foundation bed is inspected and approved by the Engineer’s representative.

In case of multi-layer soling, care shall be taken to stagger or “break” all joints in placing subsequent courses of soling. No brick shall be laid on loose earth or earth filling which are not compacted to the desired degree.

3.7 BRICK ON END EDGING

3.7.1 Materials

Bricks shall comply with requirements of First Class bricks.

The binding sand will have a minimum Fineness Modulus of 1.00 and shall be clean, and free of any organic matters.

3.7.2 Construction requirements

Bricks shall be laid on end edging with their longest side vertical or inclined to a certain degree with the alignment of the road and short side perpendicular to the road including necessary excavation filling and ramming to the satisfaction of the Engineer. The completed work shall be true to line and level and grade as indicated on the drawings. Interstices between brick edging and adjacent paving or soling shall be filled by brushing in sand until voids are filled, the edging shall be sprinkled with water.

3.8 HERRING BONE BOND BRICK PAVEMENT

3.8.2     Materials

The materials shall comply with the requirements of first class bricks.

3.8.3     Construction Methods

The bricks shall be laid either flat or on edge with the shortest side vertical, in a single layer in a herring bone pattern to the lines, grades, levels, dimensions and cross section shown on the drawings and as required by the Engineer. The edges/lines of the layer shall be made with cut bricks to produce a line, which is compatible with brick soling. The joints shall be filled with sand brushed in and the completed layer shall be sprinkle liberally with water .

3.9 CEMENT CONCRETE (C.C.) WORKS

3.9.1     Materials

Cement shall be Ordinary Portland Cement Type-l, sand shall be 50% local sand with minimum FM 1.2, 50% sylhet sand with FM 2.5, coarse aggregate shall be either crushed stone or picked jhama brick chips as specified in Bill of Quantities, water shall be potable water.

3.10.3   Construction Requirements

The specification shall be the same as for R.C.C works excepting that:

(i) No reinforcement will be used.

(ii) Strength/Proportion shall be as noted in Schedule of Items;

(iii) 20mm downgraded chips of stone shall be used as coarse aggregate or as specified in Schedule of Item.

(iv) The curing shall be done for 7 days minimum;

(v) Wooden or steel tempers or rammers in lieu of vibrators may do compaction of concrete.

If C.C. work is done over brick soling, it shall be sprinkled with water so that no loss of water from concrete can occur due to absorption of water by dry bricks. In case sub soil water tends to rise and wash away C.C. work in foundation, while this is being done, dewatering of foundation bed shall be done by making sumps and using pump or manual labor .The dewatering process shall continue until the concrete has set.

In order to improve bond with masonry/concrete work coming above it, if required, the surface shall be roughened before it reaches initial set, by scouring with the help of a pointed tool or wire brush.

3.10 CEMENT CONCRETE IN FLOOR

3.10.2   Materials

Same as in Article 3.10.1.

3.11.3   Construction Requirements

Construction shall be done as per requirements of drawing and the method shall be same as described in 1.10.

3.11 DAMP-PROOF COURSE (DPC)

3.11.1   Materials

Coarse aggregate shall consist of crushed stone chips graded from l2mm to 6mm, fine aggregate shall be Sylhet sand of F.M. 2.5 minimum. Cement shall be Ordinary Portland Cement Type-1, water shall be potable water.

3.11.2   Construction Requirements

The surface over which the DPC is to be laid shall be thoroughly scrapped to remove mud, dirt etc. and washed clean with clean water and allowed to dry, shuttering shall be done on both sides of the wall where DPC is laid over walls. The shuttering shall be strong and so fixed that it does not give in or gets disturbed during compaction and the concrete slurry does not leak out.

The concrete prepared by mixing the ingredients shall be laid and tempered thoroughly to make a dense mass.

The top surface of DPC in walls shall be in the same level of floor finish and shall not be carried across the doorways or other openings. The upper layer of cement concrete floors shall be continued over such openings and shall be laid at the same time as floor.

The base of the DPC shall be even. Uneven base shall cause retention of air void between the base and the DPC, which is not desirable.

3.12 REINFORCED CEMENT CONCRETE (R.C.C) WORK

3.12.1   Materials

3.12.1.1 Cement

Ordinary Portland cements Type-l conforming to ASTM C-150 or BDS 232- 1974. It shall be free from any hardened lumps and any foreign material other than the manufacturing ingredients. Cement shall have a minimum 90% of particles by weight passing the 75 micron sieve. Cement shall not be stocked higher than 6 bags.

3.12.1.2 Fine Aggregate (Sand)

Fine Aggregate shall consist of well-graded clean natural sand, free from injurious amount of organic impurities and deleterious substances and shall have a fineness modulus of not less than 2.50.

3.12.1.3 Coarse Aggregate

Coarse Aggregate shall consist of well-graded, mechanically crushed stone chips as specified on the structural drawings and/or B.Q. and shall be free from any adherent coatings.

Coarse aggregate shall consist of well graded hard angular fragments of broken or crushed boulders free from adherent coatings and conforming to the following grading requirements:

Designated sizes	Percentage by weight passing US Standard sieves having square openings
	38 mm	25 mm	20 mm	12 mm	10 mm	No. 4	No. 8
25 mm down graded 20 mm down graded 12 mm down graded	100 - -	95-100 100 -	- 90-100 100	25-60 - 90-100	- 20-55 40-70	0-10 0-10 0-15	0-5 0-5 0-5

The aggregate shall be well shaped with minimum angular or flaky pieces and shall be clean and free from deleterious substances. The unit weight of coarse aggregate should not be less than 1570 kg per cubic meter and the percentage wear on Los Angeles Abrasion test should not be more than 30.

3.12.1.4 Steel Reinforcement

Steel reinforcement shall conform to the specification as stated in "Material" under the heading Reinforcing bars' .Bar manufactured only from billet steel shall be used as reinforcing bars. Bars produced from scrap shall not be used as reinforcing bars under any circumstances. The Consultant shall identify the source of reinforcing steel from where the Contractor shall have to collect the bars. Prior to placement, bars shall be tested in the BUET or Consultant's testing laboratory to ascertain its quality.

3.12.1.5 Water

Water for use in concrete shall be subject to the approval of the Engineer and shall be potable, clear and free from injurious quantities of oil, alkali, salts and other substances that may be injurious to concrete and reinforcement and shall contain no more than 0.2 percent solids by weight. Suitability of water for use in Concrete shall be established by laboratory testing of samples.

3.12.1.6 Admixtures

Admixtures or cement containing additives shall be used where mentioned and .with the approval of the Engineer.

Where water proofing properties are particularly required by the work, concrete shall be mixed with "SIKA PLASTOCRETE SUPER", "FEBPROOF", "SUPER BARBARA 05" "IMPERMO" or similar admixture in approved quantity as per approval of the Engineer.

3.12.2 Composition of Mix

The strength requirement and workability shall govern the mix proportion for each class of concrete:

Class of Concrete	28 day cylinder crushing strength (minimum)	Place of Use	Aggregates		Minimum Cement per Cum
			Fine	Coarse
Concrete-I	28 Mpa	In column, wall and beam	Sand FM 2.5	20 mm down graded	350 kg.
	28 Mpa	Mat, Slab, Stair and drop wall, railing and all other RCC works as specified in schedule	Sand FM 2.5	20 mm down graded	350 kg
Concrete-II	21 Mpa	In DPC	Sand FM 2.5	12 mm down graded	300 kg
Concrete-III	17 Mpa	In boundary wall, road, patent stone and all other works as specified in schedule	Sand FM 2.5	20 mm down graded	300 kg
Concrete-IV	15 MPa	Paving slab on roof	Sand FM 2.5	12 mm down graded	250 kg
Concrete-V	14 MPa	Cement concrete	Sand 50% FM 1.2 50% FM 2.5	20/12 mm down graded	215 kg
Concrete-VI	(1:5:10)	In weak soil pit filling and temporary concrete	Sand 50% FM 1.2 50% FM 2.5	20/12 mm down graded brick chips	150 kg

3.12.2.1 Trial Mixes

Trial mixes for every class of concrete with representative materials from site shall be prepared by the Contractor in presence of Consultant's representative and carried to the laboratory in accordance with approved procedure. The nominal strength in these tests shall exceed the specified minimum strength by at least 20%. No concrete shall be placed in the permanent works until the relevant mix has been approved by the Engineer.

3.12.3   Preparation before Mixing of Concrete

Before mixing concrete, preparation shall include the following:

a) All equipment's for mixing and transporting concrete shall be cleaned.

b) The platform where the concrete shall be poured from mixer machine shall be cleaned with water and free from debris and other harmful materials.

c) Containers for measuring coarse aggregates, sand, cement, water shall be checked and approved by the Site Engineer.

d) All debris shall be removed from spaces to be occupied by concrete.

e) Forms shall be properly cleaned.

f) Coarse aggregate shall be thoroughly watered, cleaned of all foreign materials, silt and mud.

g) Reinforcement shall be thoroughly cleaned of deleterious coatings.

h) Concrete blocks for maintaining clear cover shall be properly placed.

i) Water shall be removed from the place of deposit before concrete is placed.

j) All laitance and other unsound materials shall be removed before additional concrete is placed against hardened concrete.

k) All reinforcements shall be checked to verify whether the rods of the specified number, diameter, length, shape with proper laps have been provided and necessary clearance maintained as shown in the design drawings. It shall also be checked whether the rods have been tied rigidly by wires, with the correct spacing in between. The effective depth shall be checked to see whether it conforms to that shown in the drawings.

l) No rectification works, for any part of the proposed R.C.C work, whether it relates to bending, binding of the reinforcement, or the correction of formworks shall be allowed to be left for the day of the casting of the concrete. All such rectification's and correction shall have to be done and completed on the day before casting is taken up.

m) If any casting work is done over load bearing brick wall the supporting brick wall shall be smoothened to avoid adhesion or grip of the concrete with wall resulting in cracks in the wall due to contraction and shrinkage stresses developed when setting. This may done by plastering the top surface of the wall and neat cement finishing and properly coming with water and then placing polythene sheet on the top of the wall before laying concrete.

n) Vibrator shall be kept ready for vibrating the concrete.

o) All scaffolding and shuttering work shall be carefully and thoroughly checked to avoid any loose joint, support which might give in during casting.

p) Availability of enough quantity of cement, coarse and five aggregates shall be checked for completing the casting work.

q) Shuttering shall be properly wetted before laying of concrete.

r) It shall be checked whether conduits, pipes and other fitting that shall remain inside the concrete have been properly laid and placed.

s) Opening for fixing W.C. pans, pipes, clamps for hooks shall be kept in the forms before casting concrete, so that concrete is not partially dismantled and disturbed afterwards.

3.12.4 Mixing

Concrete shall be mixed in concrete mixer of approved type and appropriate capacity.

Each batch shall be thoroughly mixed for a period of not less than 1.5 minute after all materials including the water are in the drum and during this period the drum shall be in the mixing position and revolve at uniform rate of not less than 14 or more than 20 revolutions per minute. The cement and sand shall be toughly mixed in dry condition.

The batch shall be so charged into the mixer drum that some water shall enter in advance of the cement and aggregate. The entire content shall be removed from the drum before the succeeding batch is introduced.

Concrete shall be mixed in quantities required for immediate use. Concrete shall not be used which has developed initial set or which is not in place within thirty (30) minutes after the water has been added. Re-tempering of partially hardened concrete by remixing with or without additional materials or water, or by other means will not be permitted. The inside of the mixing drum shall be kept free of hardened concrete at all times. Mixers which have been out of use for more than 30 minutes shall be thoroughly cleaned before any fresh concrete is mixed. Unless otherwise agreed by the Engineer, the first batch of concrete through the mixer shall contain only two thirds of the normal quantity of coarse aggregate. Mixing plant shall be thoroughly cleaned before changing from one type of cement to another.

3.12.5 Consistency of Concrete

The consistency of concrete shall be determined following evaluation of the placement conditions for each individual section of the work to be decided and approved by the Engineer. Mix proportions and consistency shall produce a dense, well compacted concrete with a minimum tendency to segregate under placing conditions, free from sand streaks, honeycomb, air-pockets, exposed reinforcing steel and other forms of structural weakness or unsatisfactory appearance.

3.12.6 Transport and Placing

A most thorough and careful design can be completely defeated by the improper practices in the handling of ingredients and placing of concrete. Unrestrained dropping, horizontal flow of concrete is extremely harmful and shall not be tolerated. Concrete shall be so transported from the mixer and placed in the form that contamination, segregation or loss of the constituent materials does not occur. Before placing the concrete, all form work, space and the reinforcement contained in it shall be thoroughly cleaned of all extraneous matter. Care shall be taken to fill every part of the forms, to work the coarse aggregate back from the face so that sufficient mortar will be flushed from the mass to form a smooth surface, and to force the concrete under and around reinforcing bars without displacing them.

Walking on recently poured concrete shall not be allowed.

3.12.7 Compaction of Concrete

Concrete, during and immediately after placing, shall be thoroughly compacted by mechanical vibration. The vibration shall be internal unless otherwise authorized by the Engineer.

For compaction of concrete, the Contractor shall conform to the requirements of ACI309.

Vibration shall be of a type and design approved by the Engineer. It shall be capable of transmitting vibration to the concrete at frequencies of not less than 4,500 impulses per minute.

The intensity of vibration shall be such as to visibly affect a mass of concrete of one inch slump over a radius of at least 450mm. 

3.12.8 Construction and Expansion Joints

Expansion joints shall be constructed at the locations and to the dimensions shown on the plans. Position and detail of construction joints, not shown on the plans, shall be planned in advance and approved by the Engineer Placement of concrete shall be in a continuous operation between consecutive joints.

3.12.9 Special Casting Process for Columns and R.C.C Wall

Minimum of construction joints shall be allowed in beams, and column of the structures. No construction joint in columns from below floor to bottom of beam shall be allowed, column must be cast in a lift, to avoid any construction joint below lintel level. Special shuttering with opening at middle height shall be used for the facility of casting. The opening shall be closed after casting of concrete upto that level without disturbing the green concrete. The Contractor shall prepare shuttering details ahead of actual work and shop drawings are to be approved by the Engineer. In any case the safety and stability of formwork shall be the Contractor's responsibility. No construction joint shall be allowed between beam, web & roof slab of building. For wall & water reservoir no concrete shall be placed from a height of more than 1.0m and the shuttering of the wall shall not be more than 1.25m in height.

3.12.10 Water Reservoir

Admixture of Sika Plastocrete Super (IS 2645-1975 and IS 9103-1979) 0.2% by weight of cement or similar product of approved quality at manufacturer recommendation for water tank is to be used in bases and walls of R.C.C. reservoirs.

3.12.11 Control Tests for Concrete

Sampling: The number, frequency and location of batches to be sampled shall be decided by the Engineer. The method of sampling shall be according to ASTM C-172.

Slump: This determination shall be made at the commencement of concreting, on the occasion of each change in mix proportions, and thereafter as desired by the Engineer. The testing shall be in accordance with ASTM C-143, current issue.

Compressive Strength: Test cylinders 150mm in diameter and 300mm high shall be made at the site of the work in sets of three (3) from each thirty (30) cubic meter of each class of concrete or fraction thereof or as directed by the Engineer.

Casting and curing the concrete cylinders shall be in accordance with ASTM C-31, current issue. Testing of cylinders shall be done in accordance with ASTM C-39, current issue; one cylinder at 7 days and 2 at 28-days. Cylinder at 7 days test shall not be less than 70% of the specified (design) strength.

If the Engineer allows cubes to be tested instead of cylinders, the cube strength shall be at least 25.0 percent higher than the cylinder strength specified.

3.12.12 Formwork and Scaffolding

Formwork may consist of steel sheets of minimum thickness of 14 BG or wooden planks of hard wood of approved variety having a minimum thickness of 45mm with necessary battens, struts, stringers, beams, ties, etc. In case of wooden planks the same shall be new and shall not be used more than three times in contact with concrete.

All formworks, especially for fair face concreting, must be 12 BG steel sheets and should be dented, rust free by using of sanding disk etc. before every lift of casting. Laminated board or the like may be used for formwork for a fair faced finish.

Form lining shall be in largest practicable panel to minimize joints. Under usual conditions the following minimum periods between concerning and the removal of formwork shall be observed:

Vertical sides excepting beams              48 hrs

Vertical sides of beams                          48 hrs

Soffits for span of 6 meter or fewer                     14 days

Soffits from span of over 6 meters                      min. 21 days

3.12.13 Embedded pipes and conduits

The Contractor shall co-ordinate among all trades like civil, electrical, plumbing, mechanical etc. in placement of pipes, conduits, equipment and other accessories and shall provide necessary opening in the slabs. Concrete shall not be poured before placement of pipe and concealed service lines.

Conduits shall not be spaced closer than 3 diameters or widths on centers.

3.12.14 Surface Finish and Remedial Treatment of Surfaces

Unless otherwise provided on the plans, all reasonably true and even surfaces, which are of inform color and texture, and free from stone pockets, honeycomb, depressions or projections, shall be considered as acceptable surfaces. Immediately after the removal of forms, all cavities produced by form ties and all other holes, broken comers or edges and other defects except air bubble holes, shall be cleaned and after having been kept saturated with water for a period of not less than two hours shall be completely filled, rammed and made good with a mortar or concrete of the same proportions as used in the concrete being finished.

The holes shall be completely filled by use of a pressure gun or hand rammed method as directed by Engineer's representative.

Any remedial treatment to surfaces' shall be agreed with the Engineer following inspection immediately after removing the formwork and shall be carried out without delay. Any concrete, the surface of which has been treated before being inspected by the Engineer, shall be liable to rejection.

Broom finishing shall be made for all slabs to receive artificial patent stone, terrazzo flooring, and using wire broom after the concrete is partially set.

3.12.15 Curing and Protection

Concrete shall be protected against harmful effects of weather for a period of not less than seven (7) days immediately following the placing of concrete.

All concrete surface shall be covered with two thickness of wet burlap which have been spot stitched, or wet jute felt or gunny bags as soon after placing of concrete as it can be done without marking the surface and kept thoroughly wet by continuous sprinkling of water for a period of not less than 21 days after the concrete has taken its filial set.

In lieu of continuous sprinkling, plastic sheeting or plastic coated burlap may be used to prevent moisture loss. The concrete shall be pre-moistened and the plastic sheeting shall be held securely in place so that positive moisture seal is provided to retain the curing moisture during the 14 days curing period. From of perforated sheeting shall be without delay repaired or replaced with acceptable material.

Ponding, which is most efficient method, shall be used for curing slabs. For the first 18 to 24 hours, the exposed surface is covered with moist hessian or canvas. After that small bank of dykes of lean mortar are built around and along the slab, into number of rectangular ponds and filled with water. This method is suitable for floors, roof, slabs etc.

3.12.16 Testing Requirements

Concrete shall consist of a mixture of Portland cement, fine and coarse aggregate and water. The proportions in which the various ingredients shall be used in the concrete mix for various work, shall be designed in accordance with the specified strength and suitable workability. Lateral shall conform to the requirements specified below and in the relevant sections Material Specifications.

Construction shall be according to these specifications. Contractor shall follow the following standards of American Society of Testing Materials along with the Building Code Requirements for Reinforced Concrete ACI 318-89 for Specification not covered in these Specifications. In case of differences between specifications contained in this book and those of ASTM or ACI, the specifications specified in this book shall stand.

3.13 PILING

3.13.1 Piling Work by Direct Mud Circulating Method

a )        Boring Operation

The piles shall be bored (by direct mud circulation method using Bentonite as Drilling fluid), cast-in-place reinforced concrete piles of nominal diameters as per design and drawing. The nominal diameter of piles is defined as the inside diameter of the temporary guide pipe which is used to carry out the boring and which is later on withdrawn as described hereafter .

b )        Advancement of Guide Pipe

The guide pipe shall be installed at the surfaces and therefore boring shall be executed by means of a chisel attached at the end of API rods. The borehole shall be filled with drilling slurry, which circulates through the API rods and the chisel at the base. The slurry shall flow up along the sides of the boreholes and cuttings are removed to the surface where they are separated from the slurry by decantation and the use of demander. The same slurry after removal of the cutting may be recalculated. Because of high viscosity (specific gravity being 1.2 to 1.3) the slurry stabilize;  the side of bore hole and in addition the hydrostatic head due to higher specific gravity does not allow the bore holes to collapse, and also the back flow of water into the bore hole is avoided. Further the bentonite forms a thin film on the side and acts as a further protection against caving-in.

3.13.2 Concreting of Bore Holes

a )        Mix -Proportions

The most reliable results in concreting under water in a confined space are obtained when the slump of concrete being deposited is controlled within the limits of between l50 mm to 200mm for standard slump cone.

b)         Placing

The piles shall be concreted by means of the method using tremie pipes. The 200mm dia tremie pipes shall be placed in the borehole so that they are about 300mm above the base of the hole. A funnel shall be fixed on top of the tremie pipes and concrete shall be introduced into the funnel by means of concrete bucket.

c)         End of Concreting

As concreting proceeds the level of the slurry will rise in the guide pipe and/or flow through the top of guide pipe, concerning shall continue until it has reached an elevation of minimum 1.5 Meter higher than the soffit of future pile cap which means the cut-off level of pile.

3.13.3   Penetration of Piles

Piles designed on the basis of soil tests are of different length but actual length of piles shall be determined on the basis of actual load test as described later in this section. The Engineer-in-charge may at his own discretion order the Contractor to vary the penetration of some or all the piles as the case may be.

3.13.4   Limitation of Boring Sequence

No boring operations shall take place nearer than 3 Meter from any pile for which concerning operations are in progress or from any newly completed pile until at least two days have elapsed from the last concerning operation on that pile.

3.13.5 Samples and Boring Logs

Two soil samples shall be taken from the bottom 300mm in each borehole and shall be preserved in sealed and adequately leveled glass until personally inspected by the Engineer-in-charge who shall then issue instruction regarding the further disposal of these samples.

3.13.6   Tolerances

The out-of-position tolerance shall not exceed 75mm (3" inches) in any direction. The out-of-plumb tolerance shall not exceed 1% (one per cent) in any direction.

The bow shall not exceed 50mm (2 " inches) in any direction. In order to control the amount of bow in the piles, exact records shall be kept of the amount of out-of-plumb of each borehole and the withdrawal of the casing or guide pipe shall be in the st1ict alignment therewith.

3.13.7 Inspection

After the boring has reached its final penetration as stipulated or as may be additionally ordered by the Engineer-in-charge on the basis of the test load results and ssser data obtained in the field, and after it has been completely cleaned of all earth and otherwise made ready to receive the reinforcement and thereafter the concrete, the Contractor shall so inform the Engineer-in-charge.

3.13.8 Pile Reinforcement

The reinforcement for each pile shall be assembled on the ground and securely tied by means of binding wire and welding in such manner as to form a rigid cage. Concrete spacer blocks specially precast for this purpose shall be securely attached to the reinforcement at a suitable spacing in such a manner as to ensure that the concrete cover is maintained throughout and that the reinforcement cage is not displaced in the caging in the course of the subsequent concreting operations. Should the Contractor prefer to lower the reinforcement cage assembly into the borehole in 2 or 3 sections, he may do so provided he observed the same lapping requirements as for assembly on the ground namely, that the main longitudinal reinforcement shall be lapped for not less than 40 bar diameters and the spiral reinforcement shall be double over these laps as approved by the Engineer-in- charge.

For direct mud circulation method when boreholes have been thoroughly cleaned and fresh bentonite slurry circulated for approximately 10 to 15 minutes, the reinforcement cage then shall be introduced into the borehole.

3.13.9 Pile Top

It has been stipulated that, the level of the piles at the end of the concreting operations must not be less than 1.5 Meter higher than the soffit elevation of the future pile cap or foundation raft. The top portions of the pile shall be inspected by the Engineer-in-charge or his representative duly authorized for this purpose, and the Contractor shall then break back the concrete in the top portion of the piles to the final elevation of the future pile caps, at the same time also exposing the length of pile reinforcement required for lapping and bond within the pile-cap.

3.13.10 Load Test (to verify the design capacity)

The load test stipulated herein is intended for the purpose of providing in the field that the penetration of piles is adequate to obtain an ultimate load bearing capacity of the piles of not less than twice the design value. A secondary objective of this pile-loading test is to establish whether any significant pile settlement is likely to occur upto the design load values.

b)         Location of Test Pile

The test pile shall be located as instructed in the field by the Engineer-in-charge.

Not less than 28 (twenty eight) days shall elapse between the end of all concreting operations on the test pile and the application of any test loads.

c)         Method of Loading

The apparatus and methods for the applications of test load must be capable of supplying known vertical loads to the top of the test pile without including any horizontal thrust, twist or movement in the pile. Full details of the proposed apparatus and methods shall be submitted by the Contractor to the Engineer-in- charge for his prior approval.

d)         Loading and Unloading Cycles

The load shall be applied to in increments of 20 percent of anticipated working  load till it reaches 200 percent. Settlement readings shall be made to an accuracy of 0.001 ft. and shall be taken after the application of each increment of load. Additional load shall not be applied until the rate of settlement under the previous increment is less than 0.001 ft. per hour or a period of 2 hours, which over is later.

(ii)        Load Test (to determine ultimate capacity)

The total settlement shall be equal to or more than 38mm for pile tested for failure.

3.13.11 Test Report

A load test report shall be submitted in triplicate and shall contain the following information: -

a) The location of the test pile with reference to previously established monuments or other permanent feature, drawn in a plan to suitable scale.

b) A bore hole log showing reduced levels of the existing ground levels, of the top of top pile, of the toe of the pile and of the ground water table and showing also the thickness and reduced levels of various soils strata encountered during boring as well as their visual classification.

c) A time-load settlement graph plotting the time in hours on the horizontal axis, the loads in tons and the recorded settlements in thousandth of a foot being plotted to a suitable scale on the vertical axis respectively above and below the common time axis.

d) A load-settlement graph with the load in tons plotted on the horizontal axis and the corresponding settlements in thousandths of a foot plotted downwards on the vertical axis all to a suitable scale and annotated with description of settlements variations with time at critical or otherwise important load values.

e) A report giving a general descriptions of the load test and copies of the load test log in tabular form with observations of loads settlements and time and remarks concerning any usual noteworthy occurrences during the entire operation;

3.13.12 Steel casing

This part of the specification deals with the permanent steel casing. For steel casing used during the boring of the pile see section below-

The steel of the casing shall confirm to AASHTO standard specification M 183-79 (ASTM A36) or equivalent.

The minimum wall thickness of the permanent steel casing shall 10 mm. The minimum length shall be from 10cm above the bottom of the pile cap to 5m under the river bed or into firm strata. If the permanent casing is used in the boring operation or if the handling and transport require a greater thickness to avoid deformation or buckling, the increased wall thickness shall be provided by the contractor at his own expense.

3.14 REINFORCING STEEL IN CONCRETE

3.14.1   Materials

Reinforcing steel shall be of 60 Grade, deformed bars from billet steel as specified on the structural drawings and shall meet the following requirements.

Quality of reinforcement steel, its properties including strength, elongation, bending, splicing, hooking, covering and all related events shall be in accordance with the requirements of BDS 1313-1991 and ASTM A615M.

3.14.2   Bending of Reinforcement

All reinforcement bars shall be bent cold to pertinent dimensions using bending appliances and method approved by the Structural Engineer.

3.14.3   Placing of Reinforcement

Reinforcement shall be placed, supported and maintained in the position shown in the Contract Drawing and shall be checked and approved by the Engineer before placement of concrete begins. Unless otherwise permitted by the Engineer, all intersecting bars shall be tied together with double layer of 22G black iron wire and the ends of wire shall be turned into the main body of the concrete. Clear cover must be maintained to the side of reinforcement as shown on the drawing by using concrete blocks or separators.

3.14.4   Splicing of Reinforcement

No splices shall be made in the reinforcement where not shown in the drawing. Wherever it is necessary to splice reinforcement at points other than those shown on the plans, Drawings showing the location of each splice shall be submitted to and approved by the Engineer before the reinforcing steel is placed.

3.14.5 Supports

Precast concrete blocks or metal supports of adequate strength, of proper dimension and in sufficient number shall be used for supporting the bars in position. Blocks shall be of a shape acceptable to the Engineer and designed so that they will not overturn when concrete is stored. These chairs when used shall provide proper cover as required and the numbers shall be as decided by the Engineer.

3.14.6   Welding of Reinforcement

Reinforcement in structures shall not be welded except where permitted. All welding procedures shall be subject to the prior approval of the Engineers in writing. In pile reinforcement welding may be necessary and shall be done in accordance to the drawing and with the approval of the Engineer. Welding for connecting the damaged portion of the reinforcement shall be allowed on both sides of the Re-bar and shall be 50mm of welding length on both sides and on ends.

3.14.7   Concrete protection for Reinforcement

Unless otherwise shown on the plans, the clear covering of reinforcement for different types of members shall be as follows: (please also see structural drawing)

Mat bottom                                                                   75 mm

Mat side                                                                        50 mm

Column

All sides, above FGL                                                     40 mm

Beam

Side, Top and Bottom                                                    40 mm

Walls (Above 250mm) Exposed face                              50 mm

Inside face                                                                    20 mm

Slab & Stair

Bottom                                                                          20 mm

Top                                                                              20 mm

3.14.8   Protective Coating

All exposed reinforcing steel at construction joints shall be protected with a brush coat of neat cement, mixed to a consistency of thick paint, within one week after the placing of the initial concrete, unless it is definitely known that the steel will be embedded within 60 days. This coating shall be entirely removed, by lightly tapping with a hammer or other tool, more than one week previous to the placing of the final pour.

3.15 BRICK WORK 250MM THICK AND ABOVE

3.15.1   Materials

All materials shall meet the requirement of the relevant sections of Material Specifications.

3.15.2 Mortar: Mortar of brickwork unless otherwise required shall consists of 1 part of cement and 6 parts of sand by volume.

The mixing shall be done on a clean hard platform with watertight joints to avoid leakage. The mixture should be covered with polythene sheet or other means so that dust or other foreign materials cannot be deposited. At the close of each day's work, the mixing trough and the pans shall be thoroughly cleaned and washed.

Mortar shall be mixed in quantities required for immediate use within 30 minutes of mixing. Mortar, which has taken its initial set, shall, on no account be used on the work, nor shall it be remixed with or without additional materials or re tempered by other means.

3.15.3   Construction requirements

No bricks shall be used until they have been thoroughly soaked in clear water for at least eight hours. Soaking shall be discontinued one hour before use. Care shall be taken that the bricks are clean and free from lime or dirt of any kind. If necessary, bricks shall be scrubbed clean by steel brush and washed. Water in soaking vat shall be replaced at regular intervals to avoid concentration of salt and dirt. Vat for the soaking of brick shall be constructed above the ground with a height of about 1 meter and size enough to soak sufficient for a days work. For clearing the dirty water a hole shall be kept at the bottom of one side. The vat shall have two chambers, one for soaking brick and one for clean water to be used for mixing mortar. After the days work, the vat shall be cleaned, filled with fresh water and sufficient number of bricks shall be submerged in the vat for overnight soaking.

3.16 125MM THICK BRICK WORK

3.16.1   Construction Requirement and Materials

Materials and method of construction shall be as stated in item 1.18 except that the mortar shall consist of 1 part of cement and 4 parts of sand.

3.17 PLASTER ON BRICK MASONRY

3.17.1   Materials

Materials shall meet requirements specified below and in the relevant section of Material Specifications.

a. Cement shall be Ordinary Portland Cement Type-I ASTM C-150 or BDS 232:1974 unless stated otherwise"

b. Sand shall be clean well-grade natural sand having a fineness modulus of 1.20. Sand shall be washed carefully in water to get rid of the trouble of saltpeter action in plaster and dampness to the wall due to efflorescence. Sand shall be screened by a 100 mesh wire netting sieve.

c. Water shall be potable and clean and contain no salt or organic materials.

d. Admixture shall be mixed with the cement mortar of approved quantity where item in BOQ is specifically mentioned.

3.17.2   Surface preparation

Before application of plaster, the joints in brick walls shall be adequately raked out where necessary and smooth concrete surfaces shall be roughened to provide key. The surfaces shall be scrubbed clean of loose materials and soaked with water and kept damped for 24 hours in case of brick masonry.

3.17.2   Construction requirements

All concealed utility service lines, conduits, pipes, clamps, door/window frames and other inserts must be in position before plastering commences. Chiseling and patch repairing of plaster shall not be permitted.

Cement and sand properly mixed with water in the proportion as specified shall be laid on clean walls to a thickness of 12mm. Thicker plaster on an average upto 20mm may be necessary for the uneven face of the 250mm wall. The surface and level of plaster should be checked by placing the straight edge horizontally, vertically and at different angles.

3.18 PLASTER ON R.C.C SURFACES

3.18.1   Materials

Materials shall be same as plaster on brick surface.

3.21.3   Construction Requirement

When a flat smooth concrete surface such as ceiling, column or beam shall be plastered, the surface shall be roughened beforehand by picking thoroughly with a suitable sharp picking tool and then watered. Plaster shall consist of 1 part cement and 4 parts sand and have thickness of 6mm and shall be applied in a single coat, where plaster on concrete surface is required 12mm thick, it shall consist of two coats, under and finish. The under coat shall consist of a grout application and shall have minimum thickness of 6rnm and shall be leveled with straight edge and scratched for key.

3.19 NEAT-CEMENT (SKIRTING/DADO)

3.19.1   Materials

Materials shall meet requirement as stated in item in 3.17.1.

3.19.2 Construction requirements

Wall plaster, if any, shall be removed along the floor to the required height and the surface shall be thoroughly scrubbed and wetted before applying the underbed. The second undercoat shall have a nominal thickness of6mm'and the total built-up thickness will be same as that of the plaster on the wall. A3mm deep and 3mm wide groove shall be formed where skirting/Dado meets wall plaster.

The skirting/Dado shall be installed flush with the finished wall surface. The intersection with the floor shall be a right angle and the top of the skirting/ Dado shall be straight and sharp.

The underbid shall be laid as uniformly as possible and allowed to become firm before scratching for key and subsequently allowed becoming thoroughly dry before applying the second. Undercoat. A neat cement paste 3mm thick shall be spread evenly over the second coat and shall be steel trowelled under firm pressure to produce a dense uniform smooth surface free from trowel marks.

The work shall be cured and protected from weather for at least 10 days immediately following the installation.

3.20 MAKING GROOVE ON WALL SURFACE

3.20.1   Construction Requirement

The work covered by this item shall consists of making groove of 38mm wide & 25mm deep and to be provided on all types of wall surface as per drawing and direction of Engineer. Before making groove wall shall be chiseled to attain the required depth of the groove. Care shall be taken for chiseling. In case of any damage the Contractor shall make good to the damage at his own cost.

3.21 MAKING GROOVE IN R.C.C CASTING (ON RAILINGS DROP WALLS & R.C.C WALLS)

3.21.1   Description

Fair-faced concrete of drop wall, railing and R.C.C wall shall have 20mm deep grooves as shown on the drawing or as per direction of the Engineer. All horizontal grooves shall be 40mm wide in the front and 30mm wide at the back and all vertical grooves shall be 25mm wide in the front and 20mm wide at the back.

3.22 NEAT CEMENT FINISHING

3.22.1   Description

The work shall consist of applying neat cement finishing over green plaster/concrete surface using cement slurry, rubbing smooth with steel trowel curing for 7 days etc. complete in all floor or where necessary as per requirements and direction of the Engineer.

3.23 PATENT STONE FLOORING

3.23.1   Materials

Cement: Ordinary Portland Cement Type-l.

Sand: Sand shall be as specified in the Bill of Quantities.

Coarse aggregate: Coarse aggregate shall be 12mm downgraded crushed stone chips Crushed stone chips and sand shall be properly washed and approved by the Engineer.

3.23.2 Construction Requirements

Materials and construction shall be in accordance with the requirements of item 1.13. Here of for Concrete Class-m. The flooring shall be laid preferably not later than 24 hours after the floor slab is poured. When flooring is to be laid on an older concrete slab, the base surface shall be thoroughly cleaned of all loose materials by stiff wire brush, roughened if seemed necessary and washed and soaked with clean water. Surplus water shall be removed and a dense cement grouting is applied to the surface before flooring is placed.

The floor shall be divided into panels of specified sizes, which shall not be more than 16 sqm by means of wooden battens. The top of the battens shall be at the level of the finished floor surface.

The dividing battens shall be removed carefully after 16 hrs. and the remaining panels shall be completed in the aforesaid manner. Joints would be marked with thin ropes to allow cracks, if any, to form along straight line and providing neat appearance.

The work shall be cured and protected from weather for at least 10 days immediately following the laying. Curing shall be done by banding with cement sand very lean mortar or by only sand. Under no circumstances mud band shall be allowed which shall keep a permanent stain mark on the floor.

3.24 PARKING FLOORING

Cement concrete 50mm thick on parking floor slab III basement with screed finish top with concrete Class-m in a maximum section 3m x 4m and filling the 12mm thick expansion joints with premixed sand bitumen filler including preparing sub-grade, centering, shuttering, pouring concrete, breaking stone chips, screening, mixing, compacting, levelling, curing and finishing etc. all complete including the supply of all materials and labor as per drawings, specifications and direction of the Engineer.

3.25 TERRAZZO TILE FLOOR

3.25.1 Construction Requirement

Terrazzo tiles shall be if not otherwise stated 200mm x 200mm x 20rnm composed of 10mm thick terrazzo topping on a 1:2 cement-sand (F.M 1.5) base and cast in a mould press. The tiles after casting shall be kept under shade for 12 hours to set and then in water for at least 10 days to cure. The terrazzo mix shall be as stated in item 1.32. Sample tiles shall be prepared for approval before full- scale manufacturing is undertaken.

The tiles shall be soaked in water for at least 2 hours before laying. The tiles shall be laid evenly with slight pressure to ensure close contact with bedding mortar. The mortar shall consist of 1 part of slaked lime to 3 parts of surki. A thin neat-cement paste shall be trawled over then lime-surki bed immediately before laying the tiles.

3.26 GLAZED CERAMIC TILES

3.26.1 Materials

Glazed tiles shall be either local or foreign made as specified in the schedule of works. Glazed ceramic tiles unless otherwise specified, shall be standard Grade 100mm x 100mm x 6mm and 150mm x 150mm x 6mm white/colored interior wall tiles free from warpage, blemishes and dimensional defects and as per instruction of the Engineer.

Mortar for installation shall consist of 1 part cement to 3 parts sand (FM 1.5) for wall and 1:2 for floors.

Grout for tile joints shall be made of white cement coloured as and where specified with inert pigments.

3.26.2 Construction requirements

Preparation of wall surface and application of mortar bed shall comply with the, provisions of item 1.20 & 1.21. If the surface needs leveling a scratch coat of plaster shall be applied, leveled and scratched for key and allowed to dry for 12 hours before installing tiles. The setting mortar shall be applied evenly and a neat-cement paste to a thickness of about 1.5mm shall be trawled to the back of tile and the tile set on firmly tapped into place to ensure full contact. The joints shall be in specified pattern and shall not exceed 1.5mm in width.

The mortar bed shall be minimum 6mm thick and shall be cut through horizontally and vertically every 400mm to 600mm. The tiles shall be soaked in water for at least 6 hours before setting. Installation shall be controlled by strings, pegs, spacers, levels or other suitable methods to ensure correct layout and uniform leveled joints. The joints shall be grouted, cleaned and damp-cured for at least 7 days.

3.27 FLOOR TILES/NON SLIP TILE WORK  

3.27.1 Materials

Floor tiles/Non-slip floor tiles shall be of approved brand and type as mentioned in the BOQ or as approved by the Engineer. The bedding mortar shall be 1:2 cement mortar.

3.36.3 Construction Requirements

The Non slip tile shall be smooth, water proof, dust pressed with square edges and size of the tiles shall be between 150mm x 150mm or 200mm x 200mm or 300mm x 300mm. No border edging or rounding pieces will be used. Length of each size of floor/ wall shall be filled by the tiles completely. The cut sizes if used at the ends shall be equal in size and as closed to full size as possible by making either the edge or the center of tile to coincide with the vertical center line of floor/ wall. The wall/ floor on which the tile shall be applied shall be kept moistened for 2 hours. The bedding mortar in 1:2 using medium sand (FM 1.5) shall be applied. The joints in tiles shall be minimum 5mm wide, kept clean for pointing and to be filled flush with pointing material with white or colored cement mortar unless otherwise specified.

3.28 MARBLE/ GRANITE TILE FLOOR /WALL/SKIRTING

3.28.1 Materials

Marble/Granite tiles shall be of Italian/Pakistani/Indian orin polished and having approved texture, color, and size. Before laying sample marble/granite shall have to be approved by the Engineer.

3.28.2 Construction Requirements

The tiles shall be soaked in water for at least 2 hours before laying. The tiles shall be laid evenly with slight pressure to ensure close contact with bedding mortar. The mortar shall consist of 1 part of cement lime to 2 parts of sand (F .M 1.5). A thin neat-cement paste shall be trawled over the cement-sand bed immediately before laying the tiles.

Constant checks shall be made with reference to previously established levels controlling the finished wall surface. Best contiguity between the tiles shall be attempted and the joints shall be thinnest possible and filled with white cement grout. After installing, the tiles shall be left undisturbed and protected by suitably cordoning off the area for at least 15 days.

2.29 WATER PROOFING POLYTHENE SHEET

3.29.1 Description

The work covered under this item shall consist of supplying and laying in place two layers of 0.075mm thick polythene sheets over brick flat soling in floor of buildings and where needed in accordance with the applicable Plans, Schedules and Specification.

3.30 WATER PROOF MEMBRANE WORK

3.30.1. Description

This item of work shall be of approved type of reinforced petroleum asphalt sheet (Jiffy seal, Proofex, Masterpren 1250 or Equivalent) of minimum 1.40mm thickness for the area under basement raft, side of raft, outside surface of the vertical wall as per drawing and instruction of the Engineer.

3.31 PVC WATER STOPPER

3.31.1 General

This item will be done by approved type of PVC Water Stopper having 225mm width and minimum 4mm thickness for horizontal and vertical construction joint, length to be provided on site as per drawing or as per instruction of the Engineer.

3.32   LIME TERRACING

3.32.1 Description

The item shall consist of constructing a layer of lime concrete 2:2:7 on roof slabs in accordance with these Specifications.

3.32.2 Materials

Lime concrete shall consist of a mixture of 2 parts lime to 2 parts surki and 7 parts brick chips.

Lime shall be unslaked lime and shall be mixed by weight. Lime weight shall be measured at Unslaked Condition and one cubic meter of lime terracing work requires 4.60 mounds (172.16 kg) of lime. Slaked lime shall be screened through 3.35mm sieves and the residue shall be rejected. The lime stone should be brought to site and slaked in the ground of the working place.

Surki shall be made from 1st class (well-burnt but not vitrified) bricks crushed or ground to pass through a 2mm sq mesh. Surki made from underburned or third class brick shall not be used.

Brick chips (khoa) shall consist of 20mm down-graded angular fragments of broken or crushed 1st class bricks.

3.33   INSULATION ON ROOF

3.33.1 Description

The roof has to be washed, cleaned and dried before laying insulation on roof 50/75mm thick extruded polystyrene insulation held in place with paving slabs or a 75mm thick layer of suitable gravel laid on top to hold the insulation in place as per manufacturer recommendation and instruction.

3.34 PAVING SLAB ON ROOF

3.34.1 Material

Cement shall be Ordinary Portland cement Type-l, sand shall be Sylhet sand of number F.M. 2.5, coarse aggregate shall be 12mm downgraded stone chips.

3.34.2 Construction Requirement

Paving slab of 50mm thick shall be Class-IV concrete cast in blocks of 2.5m x 2.5m to 4m x 4m having clear gaps of 6mm between the blocks. The concrete laying shall be done in two operations. At first 38/25mm of concrete to be laid and then wire mesh made of 14 B W G wires having 100mm x 100mm sizes is to cut to the size of the block and laid on the concrete. Then another layer of 37/25mm concrete is to be cast on the top of the wire mesh and finished with neat cement finish. The 6mm gap between the blocks shall be filled up by bitumen and sand. The same process shall be repeated vertically at least 250mm with the parapet wall including comers of parapet -roof.

3.35 WHITE WASH

3.35.1 Materials

a) Quick or stone lime b) Gum Arabic c) Water

3.35.2 Application Method

Lime shall be slaked lime. The wash shall be prepared by mixing and stirring lime and water in such quantities as will produce a mixture of the consistency of thin cream. When sufficiently mixed, the mixture shall be stained through a clean coarse cloth. Gum Arabic in proportion of 11lb. of gum to l5lb. of lime shall be dissolved along with approved quantity of blue & zinc oxide in the strained wash.

Quantity of white wash shall be mixed at a time in such a way that one room, or a wall surface which is visible at a time can be completed.

3.36 COLOUR WASHING

3.36.1 General

Color washing shall be prepared in the same manner as white wash with addition of the approved coloring agent. It shall be mixed at one time in sufficient quantity to complete the entire unit so treated. Color wash shall be applied in the same manner and to the same specification as white wash and shall be continuously stirred. All new surfaces and any old scrapped surface shall be given one coat of white wash and minimum 2 coats of color wash. This should be done in such a way so that it gives a uniform color and texture.

3.37 SYNTHETIC POLYVINYL DISTEMPERING (SPD)

3.37.1 Materials

High quality SPD from Berger/ Elite of Bangladesh, shell lime, whiting, putty, sealer, clean water.

3.37.2 Application Method

The surface to be distempered shall be dry, well cleaned and free from efflorescence, dirt and stain of grease. The surface shall be given a thorough rub, down to remove all loose materials and all cracks and surface irregularities shall be repaired with patching plaster and filler to obtain a smooth and even surface. After the surface has been properly prepared, the wall shall be washed over twice with a solution, made from equal proportion of whiting and best shell lime. The mixing of distemper shall be carried out in accordance with the instruction issued by the manufacturer of the particular brand of distemper that is to be used.

3.38 PLASTIC PAINT

3.38.1 Materials

The plastic paint should be Robialac (Berger)/ELITE or equivalent and must be approved by the Engineer. The priming consists of appropriate type as specified for the paint by the manufacturer, and shall be applied accordingly.

3.38.2 Application Method

The surface to be plastic painted shall be dry, well cleaned and free from efflorescence dirt and stain of grease. The surface shall be given a through rub down to remove all loose materials and all cracks and surface irregularities shall be repaired with patching plaster and filler to obtain a smooth and even surface. The mixing of plastic paint shall be carried out in accordance with the instruction issued by the manufacturer of the particular brand of plastic paint that is to be used. Before staling work plastic paint shall be mixed in such way that one room can be finished with same mix. Plastic paint is to be applied with proper brushes as supplied or recommended by the manufacturer. A sample area must be prepared first and get inspected and approved by the Engineer before the full-scale work commences.

3.39 WATER REPELLENT COATING

3.39.1 Description

The item shall consist of applying 2 coats of clear silicone water repellent on exposed brick or concrete surfaces and cement plaster on wall, ceiling and elsewhere in accordance with these Specifications.

3.48.2 Materials

Silicone water repellent shall consist of sodium silicate or other alkaline silicates based clear approved product supplied in original sealed containers bearing the manufacturer's trademark.

3.40 CEMENT PAINT/ACRYLIC EMULSION PAINT

3.40.1 Description

The item shall consist of applying 2 coats of cement/acrylic emulsion paint of approved colour and Brand over a coat of priming on concrete plastered surfaces and cement render on exterior wall, ceiling and elsewhere in accordance with these specifications.

3.40.2 Material

High quality material from approved manufacturer (Weather/Aclose Master Coat) as stated in the schedule of works. The materials shall be delivered to site in unopened original container bearing approved manufactures label.

3.40.3 Application Method

Cement paint shall be of approved colour. The application of cement paint shall strictly comply with the manufacturer's instruction. The application shall preferably be carried out after a period of dry weather. Before application, the surface shall be thoroughly clean and dry .The paint shall be prepared by mixing and stirring, paint powder and water in such quantities as will produce a mixture of the consistency of thin cream. When sufficiently mixed, the mixture shall be strained though a clean coarse cloth. For mixing cement paint manufacturer's instruction details shall be followed. Prime coat shall be prepared according to the direction of the Engineer.

The surface to be cement painted shall be thoroughly cleaned of all foreign matter by using stiff wire brush, sand papering or other approved means. Cement paint shall be applied in 2 coats alternately laid on vertically and horizontally on prime coat. Each coat shall be perfectly dry before the succeeding one is laid over it.

3.41 ENAMEL PAINT

3.41.1 Materials

·       1High quality Synthetic enamel paint of approved brand.

·       Sand paper

·       Putty made of 2 parts of whiting, one part of white lead mixed together in linsed oil kneaded with wooden mallets until thoroughly incorporated. After kneading it in left for 12 hours when it is kneaded again to give smooth workable paste. Desired pigment may be added if coloured putty is needed.

·       Thinner:

3.41.2. a Surface Preparation

Whole success of painting operation depends upon satisfactory preparation of the surface to be painted and great majority of defects which occur are due to faulty preparation. Woodwork shall not be painted unless it is absolutely dry.

3.41.3. b Application Method

The timber surface shall be painted with two coats of synthetic enamel ready mixed paint of best quality and approved color over a coat of priming. The paint shall be applied on appropriate primer after the surface has been finished with filler/putty, etc. No work shall be done under conditions which are unsuitable for the production of good result. No exterior painting shall be done in rainy, damp weather.

After the wood surface is prepared, the paint shall be applied with brush and spread as evenly and smoothly as possible. All steel surface shall receive 2 coats of hard-gloss paint of approved color over a coat of anticorrosive paint. The correct timing of application of primer coat is a very important factor. Particularly when humidity is high or dew settles on surfaces in the evening or night. Roughly speaking, painting of steel work can approximately be started at about 10AM which is generally the time when all dew has evaporated.

The enamel paint should be Robialac (Berger) or equivalent and must be approved by the Engineer.

3.42 FRENCH POLISHING/POLYURETHANE BASED VARNISH

3.42.1 Materials

French polish is made by dissolving shellac in methylated spirit, 400 grams of shellac is dissolved in a litre of methylated spirit without heating. It may be coloured by adding pigment. A solution is then strained through a double thickness coarse cloth. A very small amount of plasticiser such as castor oil is sometimes added. Water proof wood varnish (YACHT BRAND or equivalent) at readily available in the market will be used as per manufacturer's instruction.

3.42.2 Application Method

French polishing to door frame and shutters three coats over a coat of primi1lg including cleaning finishing and polishing with sand paper etc. all complete in all floor. Before applying polish, the wood surface shall be clean and dry. As methylated spirit is used as solvent, French polish dries quicker, becomes hardened and more brilliant than oil varnishes but cracks and scales off. It does not withstand weathering and should be used only in superior wood works, not subjected to vagaries of the weather. After cleaning the wood surface, it is coated with a fl1ler made by mixing 250 grams of whiting in one litre of methylated spirit. When the fl1ler coat has dried, the surface is rubbed with sand paper.

3.43 TIMBER WORKS

3.43.1 Construction Requirements for Timber Doors

Timber for shutters, trims and frames shall be Silkorai/Teak/Chapalish or as specified in the Bill of Quantity Grounds, studs and blocking shall be in sound J am or other approved wood. All timber shall be free from sap, shakes, large or loose knots and defects affecting the appearance, strength and durability of construction and shall be well seasoned, dried to moisture content of 6% by weight and treated with non-swelling, non-staining water repellent paintable wood preservative.

Glue shall be waterproof approved product consisting of synthetic resin (phenolic, amino plastic or polyvinyl acetate) emulsion adhesives for wood or any other approved materials conforming BS-1204.

Knotting shall consist of a uniform dispersion of 25% flake shellac in 75% methylated spirit or other approved natural or synthetic resin in a suitable solvent and conform to BS-1336.

Stopping shall be made from white or red lead and sufficient linseed oil to produce a stiff paste and conform to BS-544.

Hardware shall be of approved material, finish, type and make and shall be complete with necessary screws, trims and all other accessories required for proper installation. All screws and accessories shall be of suitable size and type and shall match with the pigment as to material and finish.

Joinery workmanship shall be of the highest quality. All joints shall be well made, cleanly matched and tight. Verticals shall be plumb. Joints shall be put together with waterproof glue and if necessary further secured with finishing nails of softwood or with screws of hardwood.

All edges of woodwork shall be carefully trimmed and the arises eased by rounding to a radius 1.0mm.

Doorframes in masonry walls shall be installed only after the walls are in place and have been cured. Styles and rails shall be accurately cut and glued together with close fitting mortise-and-tenon joints which shall be further pinned with corrosion resisting metal pins of diameter not less than 5mm or with hardwood pins of diameter not less than 7mm. The joining shall be such as to ensure complete rigidity of framing throughout.

All faces of frame buried or hidden in masonry shall be painted with 2 coats of tar paint before erection. The frames shall be installed plumb and fixed to brick masonry with flat iron hold fasts (225 x 37 x 6)mm tongued and turned at the ends and to concrete with No. 12- 90mm long screws with suitable expansion- shields or fiber-lugs. The holdfasts and fixing screws shall be spaced not over 1 meter apart. The screw heads shall be countersunk at least 12mm below the surface and plugged.

Application of surface finishes shall conform to British Standard Code of practice CP-231.

After erection and before any finish is applied, all woodwork shall be hand- sanded using a succession of grit sizes each removing in turn all the coarser grooves created by the preceding grit. Knots and resinous streaks shall be treated with 2-3 coats of knotting applied evenly and thinly. Nail holes, cracks and cavities shall be filled in with stopping pressed well home with a stopping knife. Large holes or knots shall be plugged in with a mixture of red lead and enamel glue in equal quantities laid hot. Knotting and stopping shall extend slightly beyond the resinous area or cavity on to the adjacent surface.

Oiling shall be done with linseed oil, either raw or boiled according to whether a flat or glazed surface is required. Unless otherwise specified a mixture of raw and boiled oil shall be used. The oil shall be rubbed into the wood till the surface is dry .The oil shall be applied sparingly and excess removed to avoid a sticky surface.

A wash coat of sealer consisting of V4 kg cut of shellac shall be applied first and when dry sanded lightly. F or internal works, 2 coats of lacquer consisting of 1 kg cut of shellac shall be applied from a well charged clean brush which shall be worked on the surface no longer than is necessary to ensure even spreading. F or external works 4 coats shall be applied. Each coat of varnish shall be lightly rubbed down with fine steel wool or abrasive paper and dusted before applying the next.

3.44      DOOR/WINDOW HARDWARES

The item shall consist of supply and fitting of best quality approved size and quality hardware of doors windows or where necessary

3.45      DOOR & WINDOW PELMET

This item shall be made of wood of dimensions specified in the drawing or as directed by the Engineer. The amount of completed & accepted work measured in square meter shall be paid for at the contract unit price which payment shall constitute full compensation for furnishing all materials, labor including ruler, holder etc. complete.

3.46 SINGLE LEAF FLUSH DOOR

3.46.1   Materials

Mechanically seasoned Chittagong teak wood.

3.46.2   Construction Requirement of single leaf flush door

The single leaf flush door of approved size of best quality Bangladesh made ( as approved) shall be BFIDC or equivalent standard.

3.47 PLASTIC DOOR I UPVC DOOR

3.47.1   Description

The item shall consist of supplying, fitting and fixing factory made UPVC hollow plastic door shutter with door frame in toilet and where necessary including all necessary accessories like door lock, hinges, stopper, screw etc. all ~ complete as per Manufacturer's specification, drawing and direction of the Engineer. Before making full scale supply, the Contractor shall supply one sample door for approval of the Engineer.

3.48 METAL WORKS

3.48.1   Construction Requirements

Mild steel pipe shall be of specified size conforming to the requirements of ASTM A-53.

Structural steel shall conform to the requirement of ASTM A-36 and shall include plain structural shapes and plates cut to length or fabricated. Glazing shall be provided with 3mm thick transparent acrilic panes (sheet).

All steel surface shall receive 2 coats of hard-gloss paint of approved colour over a coat of approved anti-corrosive primer unless otherwise specified. Prior to painting, the surface shall be cleaned of mill scale, rust, oil grease and dirt. Surface not painted to the Engineer's satisfaction shall be repainted at Contractor's own cost.

3.49 STEEL DOOR ANGLE FRAME

3.49.1   Material and Construction Requirements

The work covered under this item shall consist of supplying and fabricating M.S angle frame fitted with brick masonry/R.C.C structure by cutting grooves for clamp & mending good to the damages and shutter made of 16 BWG steel sheet as per drawing including supply of all materials, welding, fabrication, hinges, locking arrangement, hatch bolt, tower bolt etc. complete.

3.50 FIRE RATED DOOR

3.50.1   Construction Requirement

Steel doors shall be paneled doors with panels having frame in fire escape as per required size for 3 to 4 hour fire rating with 16 gauge face sheets, formed, welded with internal reinforcing channels in full height of door and horizontal stiffeners welded to face sheets at top and bottom the annular space completely filled with small cell phenolic resin impregnated honey comb core bonded to the face sheets in 16 gauge hollow metal frames including vertical members, threshold, mullion etc. true to line, dimension and position, smooth finished, including supply of component parts of the panel and the frame factory finished, phosphatized, primed and finished with the one coat of silicon alkyd enamel paint, and the coats of baked enamel, their fabrication and assembly, and supplying, fitting and fixing appropriate panic hardware and automatic closing devices, packing and back-up materials, jambs, lock sets, hinges, closures, push/ pull bars, operators, rowel plugs, bolts and nuts, washers, springs, cleats, buffer blocks, caulking sealant, weather strips, conforming to standard fire rated doors for necessary smoke proofing, etc. complete with all essential fittings and accessories.

3.51 M.S. GRILL I REINFORCED ALUMINIUM GRILL

3.51.1   Construction Requirement

The mild steel shall conform with the requirements of ASTM A-53. The structural steel shall conform with the requirement of ASTM A-36. These flat and angle M.S. sections are to be cut to sizes, fabricated, welded (continuous) and to the shape and sizes of the frame as per drawing. This frame shall have two coats of synthetic enamel paint over a coat of approved anticorrosive primer. The enamel paint should be of approved colour. Each frame must have min. 10 nos. of clamps on 4 sides of the frame.

A frame should be prepared and deposited with the Engineer for his approval. Only after approval the manufacturing should start.

3.52      GRILL BY FLAT BAR FORWINDOWNERANDAH ETC.

3.52.1   Description and Construction Requirements

The work covered under this item shall consist of supplying, fitting, fixing, window or Verandah grill of any design made with F.I. bar including fabricating by M.S. angle/flat bar frame, welding, painting with two coats of Synthetic enamel paint of approved quality and color over a coat of primer etc. complete for all floor as per drawing and direction of the Engineer.

3.53      VERANDAH GRILL, GRILL GATE ETC. BY MS ROD (10MM DIA)

3.53.1   Materials and Construction Requirements

The work covered under this item shall consist of supplying and fabricating M.S rod including complete manufacturing by welding, fitting, fixing in position using M.S clamp, locking arrangement, cutting of grooves for clamp and mending good to the damages, two coat of enamel paint of an approved color over a coat of primer, scaffolding etc. complete in all floor as per drawing and direction of the Engineer.

3.54 M.S. GRILL OVER BOUNDARY WALL

3.54.1 Construction Requirement

The mild steel shall conform to the requirements of ASTM A-S3. The structural steel shall conform to the requirement of ASTM A-36. These flat M.S. sections and the round M.S. bars are to be cut to sizes, fabricated, welded (continuous) and to the shape and sizes of the frame as per drawing. This frame shall have two coats of synthetic enamel paint over a coat of primer. The enamel paint should be of approved color. Each frame must have min. 8 nos. of clamps on 3 sides of the frame.

3.55 STEEL FRAMED MAIN GATE

3.55.1 Materials a lid Construction Requirements

Mild steel shall conform to the latest British Standard specification B.S.785 & B.S. 4 Part-l:1962. The gates shall be fabricated to the details shown on the drawings or as directed by the Engineer. All features shall be strictly accurate and the gates shall not be fixed on position until these are approved by the Engineer.

3.56 ROLLING SHUTTER

3.56.1   Materials and Construction Requirements

The work covered under this item shall consist of supplying, fitting and fixing of rolling shutter made of 24 SWG G.P. sheet unit minimum 69mm width having 10mm & l2mm dia circular folding at ends, rolled in machine, locked together properly to form rolling shutter top of the shutter to be fitted with circular spring box made of 22 BWG sheet, containing best quality spring made in China, nutted with 38mm G.I pipe at one end and the other end nutted to shutter in/c fitting the G. I. pipe again with 375mm x 300mm x 6mm pankha at ends with  side guide channel (side channel consist of 50mm x 100mm x 6mm M.S. plate with 2mm x 19mm x 3mm F. I. bar middle channel consist of 2 x 150mm x 6mm M.S. plate with 2mm x 19mm x 6mm) fixed to wall or column with clamps (minimum 3mm x 25mm x 6mm), mending the damages, bottom end of shutter fitted to folder G. P. sheet (minimum l25mm width, two layer) which is again fitted to 25mm x25mm x 3mm angle, providing handle both sides, (with F.I. bar 25mm x 6mm riveted) and locking arrangement both sides, painting two coats with approved colour and brand of synthetic enamel paint over a coat of priming etc. complete in all respect as per drawing, design and direction of the Engineer (Rolling shutter must be riveted at sides with G.P sheet and patty).

3.57 GLASS WORK AT DOOR, WINDOW,  CURTAIN WALL ETC.

3.57.1   Construction Requirements

Materials and Products: Doors, windows, curtain walls etc. shall be of approved standard conforming to the U.S. Architectural Aluminum Manufacturers Association (AAMA) or ETA specifications. The frames and sash members shall be of extruded shape made of 6063- TS high quality aluminum alloy having a minimum section thickness of 2rnm unless otherwise shown on the drawings or indicated in the schedule of items and shall conform to AAMA or BTA standard.

Fasteners, Hardware and anchors: Fasteners, hardware and anchors shall be of aluminum or non-magnetic, non-corrosive material compatible with aluminum. All windows shall be provided with non-jamming latches of rocker type designed to be locked from inside. Window locks shall be flush type as per approved equivalent. The doors shall be provided with cylindrical locks and suitable built-in non-jumping latches and bolts.

Security locks shall be pin type mortice lock, 6 or 7 pins and adaptable to Master, Grand master and Great Grand Master keys. Sliding windows and doors shall be fitted with adjustable sealed bearing sheaves of durable hydrated nylon or approved equivalent. Closers, Push/pull and kick plates shall have to match with the frames. Any other hardwares to be incorporated in the work shall also match with the frame. Assembly and installation screws shall be of stainless steel. Doors, Windows, curtain walls etc. shall be installed with teflon injected expanding bolts, Sills shall contain adequate provisions for drainage. Head, sills and jamb members shall be of one piece construction.

Glass Pane: Glass shall be 6mm thick tinted dark bronze float glass panes (Japan or Equivalent) or as per drawing, schedule of item and direction of the Engineer.

Glazing Beads: Glazing beads shall be aluminum shape-in interchangeable type.

Glazing Strips: Glazing strips or channels shall be of formed neoprene of acceptable quality

Weather Stripping: Weather stripping shall be of neoprene or silicon treated woven wood or approved equal.

Joints: joints shall be mechanically done square (telescopic) joints. No mitred Joints shall be accepted. No forced fitting shall be accepted. All units shall be fabricated at the factory to accurate dimensions. It shall be rigid and designed to permit complete weather stripping. In principle, the parts should be put together by self-tapping screws.

Surface Finish: All exposed surfaces of aluminum members shall be factory finish and of substantially uniform appearance conforming to "Architectural" standard.

Accessories: Accessories necessary for proper fixing and preparation such as \ anchors, clips, fins, sub-frames, metal sills, mullion, covers, casing, other trim, cleaning anchors, glazing beads, weathering and glazing strips, hardware and mechanical operators shall be supplied ready to set in place with the door, window, curtain wall units. Steel or wood sub frames shall be painted with Zinc-chromatic primer in case of steel and with wood preservative in case of wood. Steel anchor shall be properly insulated from aluminum frame.

Sealant: Sealant shall be one part elastic compound of "Architectural" grade caulk and shall be in matching color or as approved by the Engineer.

Shop Drawings: The Contractor shall prepare detailed design of all work involved in line with the Consultants design and prepare Shop Drawings for the total work and submit to the Engineer for approval before factory fabrication. All exterior doors, windows and curtain walls shall be designed to withstand a wind pressure of 30Ib/sft.

Installation: All units shall be assembled at site under proper conditions, erected, fixed and glazed in place in strict conformity with manufacturer's instruction. All cut-out operations for hardware preparation shall be made accurately and reinforced as required. All doors, windows, curtain walls etc. shall be set plumb, square, level and in exact alignment with surrounding works and shall be securely anchored ready for operation. All joints between the masonry openings and frames hall be caulked and sealed after installation of the frames. All installation works shall be done and finished in such a way as to ensure a free and smooth operation.

3.58 WOOD STRIP FOR FIXING OF ALUMINUM CURTAIN RAIL

The work covered under this item shall consist of supplying, fitting and fixing of C.T. wood strip (62mm x 25mm x 20mm) for fixing of aluminum curtain rail as per design and drawing, fitted and fixed in position including supply of screws, nail and two coats of french polishing over a coat of priming etc. all complete as per drawing, specification and direction of the Engineer.

3.59 GLASS WORK

The work covered under this item consist of supplying, fitting and fixing glass in Aluminium doors, windows, partitions and where necessary including cost of neoprene, fitting & fixing in position, all necessary accessories etc., complete in all respect as per drawing and direction of the Engineer.

All glass shall be sheet glass or float glass of approved quality. Glass shall be flat surface, no scratch, no distortion and absolutely transparent.

3.60 RAILING WITH STAINLESS STEEL PIPE

The work covered under this item consist of supplying, fitting and fixing of railings stainless steel pipe reinforced by appropriate M.S. rod deeply anchored into concrete fitted hand rails with same quality pipe as per design, drawing & direction of the Engineer inclusive of supply of all necessary stainless steel hardware's nuts bolts, washers etc. all fabrication, installation alignments with perfect finish and mending good any damages done to other work during installation.

3.61 HAND RAIL ALONG WALL/TOP OF PARAPET

The work consists of supplying, fitting and fixing stainless steel or G.I. pipe hand rails in stair and where necessary on clamp supports in wall etc. all complete including cost of all materials, labors, fabrication, welding etc. all complete as per drawi11g, specifications and direction of the Engineer.

3.62 STAIR CASE RAILING

The work covered by this items shall consisting of manufacturing, supplying, fitting and fixing stair railing of standard height with square box post made by through welding of 2 nos. 25mm x 25mm x 5mm M. S. angle including providing wooden hand rail of 125mm x 7Smm section and 25mm x 25mm bend, engraving each box 150mm in the concrete by 50mm x 50mm x 6mm anchor plate at base, welding 38mm x 6mm F.I. bar in inclined plain with the top of the box to fit in the grooved wooden rail by necessary screws including cutting grooves in concrete, mending good the damages with C.C. (I :2:4), applying 1^st class polishing to hand rail, 2 (two) coats of synthetic enamel paint of approved quality over a coat of prime coat etc., finished in all respect as drawings, specification and direction of the Engineer.

3.63 FALSE CEILING WORK, PARTITION WALL

The work covered by this item shall consist of supplying, fitting, fixing false ceiling! partition wall by using hard board/ partex board/ ply wood/ fibre glass having specified thickness over wooden/ steel frame/aluminium as per design or drawing including, supply, fabrication of fittings, fixing frame with hanging arrangement, supply of M.S. clamp, french polishing on timber, painting on steel frame etc. complete.

3.64 FALSE CEILING

Supplying, fitting and fixing of l2mm thick gypsum board laminated by mechanical hot press with a milk white PVC membrane with aluminium T -bar frame in natural anodized finish at 600mm x 600mm in grid, suspended from ceiling by 12 SWG double ply G.I. wire fixed to the ceiling by rowel plug, screws, hooks, nails, etc., maintaining straight lines and desired finished level at bottom face with vertical wooden strut as required including making holes in slabs, or beams by electric drill machine and mending good the damages, if any, during the execution of the work including cost of all materials, accessories, scaffoldings, labor for installation, screws, nail, etc. all complete as per drawing, design, specification and direction of the Engineer .

3.65 SURFACE DRAIN

The item shall consist of 300mm or 600mm deep drains in accordance with these specifications. The surface drain shall be constructed in true line and level as per drawing and direction of the Engineering Representative. 300mm deep drains shall have 300mm clear width with 125mm thick brick wall ( 1 :4) on 75mm thick cement concrete ( class -VI) base over single layer brick flat soling. The exposed surface will have 20mm thick cement plaster (1:4) with neat cement finishing and curing at least for 7 days must be done. The surface drain of 600mm ( avg .) depth shall have 400mm clear width with 250mm thick brick wall (1:6) on 75mm thick cement concrete base over single layer brick flat soling. The exposed surface will have 20mm thick cement plaster (I :4) with neat cement finishing. Curing for 7 days must be done.

3.66 APRON

3.66.1   Description

The item shall consist of construction 50mm thick cement concrete over a layer of Brick flat soling around the structure in accordance to these specifications.

3.66.2   Construction Requirement

Cement Concrete of class-V with neat cement finishing.

Brick flat soling by first class bricks unless otherwise specified.

Sand shall be clean well graded natural sand with PM as stated in BOQ.

Water shall be same as required for concrete.

The area specified for construction of apron shall be thorou1ly cleaned, leveled & compacted to proper slope & level. Brick flat soling shall be laid over compacted earth according to specification no.1. 7, then cement concrete of class-V as per specification no. 1.10 shall be placed over brick flat soling with maintaining proper level & slope towards drain, simultaneously neat cement, finish shall be applied on top surface curing for a period of at least 7 days as prescribed in item no. 1.10 complete as per drawing & direction of the Engineer.

3.67 R.C.C PAVEMENT

Formation bed shall be prepared by excavating or filling and compacting to the required level and profile in accordance with the provision of items 1.4 and 1.6. All soft and yielding materials and other portions of the sub-grade which will not compact readily when rolled or tampered shall be removed and all depressions made by removal of such materials shall be filled with sand of F .M.1.0 and compacted and the whole formation brought to correct profile and level as per drawing.

An insulation course of sand with a minimum fineness modulus of 1.0 shall be spread uniformly over the prepared sub grade and brought to the specified thickness. After spreading, the sand shall be sprinkled lightly with an amount of water and compacted sufficiently to secure a dense surface of compacted thickness which will support the brick flat soling.

Surface course shall be in concrete Class-III prepared and placed in accordance with the provisions of item 1.13. The concrete shall be deposited on the brick fiat soling or compacted sand in successive batches for the full width between the both sides of the road or as per drawing. The amount of material deposited shall be sufficiently in excess of that required to form the pavement and to provide a small roll of concrete ahead of the screed for its full length. After being spread the concrete shall be consolidated and screened to the required thickness and profile.

Reinforcement in pavement shall be placed and secured as shown on the plans in accordance with the requirements of item 1.17 and shall be paid separately.

Constriction and expansion joints shall be constructed exactly in accordance with the details shown on plans and with best workmanship and as per direction of the Engineers' representative.

Extreme care shall be exercised in placing, compacting and finishing concrete at the joints to prevent displacement of the joints and to avoid the formation of honeycombs and voids. The concrete along the joints shall be thoroughly consolidated by the use of vibrators.

Curing and protection shall start as soon as newly-laid pavement is sufficiently, ~ hardened and shall be continued for a period of at least 7 days as prescribed in item no. 1.13.

After hardening of concrete the joints shall be cleaned and filled with sand bituminous mastic as per instruction of the Engineer.

3.68 CLINKER PAVEMENT

3.68.1   Materials

Materials shall meet requirements specified below and in the relevant sections of materials specifications.

Clinker tiles shall be 200mm x 100mm x 50mm in size well -burnt clay tiles free from cracks and edge or surface flaws.

3.89.3   Construction Requirements

The bed shall be prepared by excavation or filling as necessary to the required level and profile in accordance with items 1.5 and 1.6.

A brick flat shall be laid on the prepared sub-grade as per 1.7 and the sub-course in concrete shall be placed in specified thickness over the brick soling in accordance the items 1.10.

Clinker tiles shall be laid after the concrete sub-course has been cured for at least 7 days. The tiles shall be set in the pattern shown on applicable plans and shall be bedded in a mortar consisting of 1 part of lime to 3 parts of surki by volume. Immediately before the tiles are bedded, a thin layer of neat-cement paste shall be soaked in clean water for at least 6 hours before lying.

3.69 ANTI TERMITE WORKS

3.69.1   Materials

Government registered chemicals popularly known as the infamous "Dirty Dozen", which includes widely used material like Dieldrin, Heptachlor are quite - effective for anti-termite treatment. By use of Dieldrin, complete protection work for more than 30 years have been achieved in USA. But dieldrin is highly toxic and is responsible for environmental pollution.

3.68 ROOF TRUSS

The work under this item shall consist of supplying and fabrication of Mild steel sections, as per design and drawing for roof truss including hoisting, fitting & fixing in position with bolts and nuts or rivets or welded and providing two coats of anticorrosive paint over a prime coat of red oxide paint, including using anchor bolts with nut embedded in structure, scaffolding etc. all complete at all height as per drawing and direction of the Engineer.

3.69 C.I SHEET ROOFING

The work covered under this item shall consist of supplying & fitting fixing 26 BWG galvanized iron corrugated sheet roofing on wooden steel frame with auxiliary fitting such as galvanized screw/J-hook with nut, G.I. perlin limpet & bitumen washers, putty etc. complete as per direction, at all height.

3.70 EXPANSION & ISOLATION JOINTS COVER WORK

Wall and floor expansion joint shall be provided with two strands of bitumen impregnated coir rope tightly wedged into place and covered on the exposed face with aluminum cover with snap-in clip as per drawing

Roof expansion joint shall be provided with sand bituminous mastic. Clean coarse snad (FM 2.5) shall be thoroughly mixed with hot bitumen in the ratio of 30kg of bitumen with 1 CuM of sand and the resulting mastic, while still hot, shall be carefully poured and rammed into the full depth of the expansion joint as shown in drawing. The work shall be done when the contact surface is dry . When inserting mastic into place care shall be taken not to foul areas not designated for such application.

3.71 PROTECTION OF VERTICAL CUT

Protection work as per approved design and drawing of vertical cut of foundation pit upto required depth and area with sheet piling and / or any other standard method approved by the Engineer.

The contractor may follow the design, drawing and procedure supplied by the Consultant for protection works or he will use with approval of the Engineer, his own method, design and procedure for protecting vertical cuts and to maintain it throughout the construction period up to ground floor. The contractor will submit his design for vertical cut protection to the Engineer for approval. But the approval by the Engineer of his design will not relieve him from his responsibility.

The perceptive work should be done in such a way, the construction of foundation raft or basement will not be obstructed by these protective measures.

3.72 DEWATERING

The ground water table should be kept at least 1.5m below the lowest foundation level (approximately 7m below existing ground level). The contractor shall employ with approval of the Engineer, his own method and design for the dewatering and for maintaining it until the construction of the basement floor is complete. The contractor should submit his design and method for dewatering for the approval of the Engineer. But the approval by the Engineer will not relieve the contractor of his responsibility for the successful dewatering and maintaining it throughout the construction of basement floor.

3.73 CLEARING AFTER COMPLECTION

The Contractor shall thoroughly clean all work upon completion. Clean off all strains, marks, spots, and disfigurements from all works, touch up as required, clean all windows panes, remove all rubbish and debris from building and site and leave premises clean and tidy and fit for occupation in all respects and to the entire satisfaction of the Engineer.

3.74 REGULATORY COMPLIANCE

The Regulatory Compliances shall be followed and maintained as per the provisions mentioned in the BNBC, Building Act 1996, Real Estate Act 2010, and other provisions imposed by RAJUK.

PART 3 : SPECIFICATIONS

SECTION 3B    : MEP WORKS

1. Introduction

This is the proposed engineering designs and resultant spatial and system requirements for building services. The building will be used by multiple tenants and the building services designs will provide for single tenants per floor. The proposed development will be approximately comprising a 25 storey tower above 4 basement floors.

This development will consist of:

• Basement 4 Floor: parking, ramp, stair, lift PIT, drivers waiting, fire pump room etc (1024m2 approximately.)
• Basement 3 Floor: parking, ramp, stair, lift core, driver waiting, BMS room etc(1024m2 approximately.)
• Basement 2 Floor: parking, ramp, stair, lift core, main EME rooms etc(1024m2 approximately.)
• Basement 1 Floor: parking, main, stair, lift core, main EME rooms etc.(1024m2 approximately.)
• Ground Floor: Reception area, Lift lobby, toilet rooms and retail space.
• st – 2nd Floors: lift lobby, toilet rooms, pantry room, Office Space.
• 3rd Floor: Restaurant area, lift lobby, toilet rooms, Kitchen room .
• 4^th-25th Floor: Typical office area, lift lobby, toilet rooms, pantry room.
• Roof Floor: ODU, Solar Panel, Exhaust fan etc, lift machine rooms, water tanks and booster pump room.

Building services covered by this report are:

• VRF Air Conditioning & Ventilation
• Electrical & Communications
• Fire Protection
• Sanitary
• Vertical Transportation

Once approved, this report will form the basis for detail design and documentation for the construction of the building.

2. Mechanical Services Design Report

2.1. Introduction

This document has been prepared to outline the design for Proposed Tower a new office tower to be developed in Dhaka, Bangladesh.

2.2. Scope of Works

The mechanical services will be appropriate to a good quality office building. All commercial areas will be documented to an open plan layout for future fit out. Services will generally comprise the following:

Air conditioning to all office areas, commercial areas and lobby areas

Tempered cooling for lift motor room

Mechanical Ventilation Systems

- Toilets

- Car parks

- EME rooms

Fire Smoke Control Systems

- Stairwell pressurization system for basement floors.

- Natural smoke ventilation system for above ground floor

- Basement car park smoke control system

2.3. Standards and Regulations

Design criteria adopted for mechanical services are consistent with industry accepted standards for the development and will meet or exceed the requirements of the relevant Acts and Standards. Some of the standards to be adopted are as follows:-

a) Bangladesh National Building Code BNBC

b) American Society of Heating, Refrigeration and Air-Conditioning Engineers ASHRAE

c) National Fire Protection Association NFPA

2.4. Design Conditions

2.4.1. Building Fabric

The mechanical services design will be based on the façade details provided by the architect. Insulation shall be provided as part of the building works under all exposed roof slabs and behind façade spandrel panels, for good performance of the air conditioning system.

2.4.2. Design Temperature Conditions

External

35.5°C dry bulb maximum

27.5°C mean coincident wet bulb temperature at the above dry bulb

36.0°C dry bulb maximum for air cooled condensers

These figures are taken from the Bangladesh National Building Code and are values which are equaled or exceeded by 0.4% of the total hours during the summer months of May through September.

Internal

Lift motor room 27⁰C

Main lobby / lift lobbies 25⁰C

General office space 24⁰C

Control Tolerance: ± 1.0°C dry bulb; humidity controls are not provided other than by virtue of cooling coil operation

Occupancy

Open plan office space 1 person / 8m2

Typical Lift Lobbies 1 person / 15m2

Main Lobby/Lounge at Ground 1 person / 5m2

Equipment / Lighting

Open plan office space 20W/m2 / 9W/m2

Typical Lift Lobbies nil / 9W/m2

Main Lobby/Lounge at Ground 20W/m2 / 9W/m2

The air conditioning design is based on the provision of blinds for perimeter areas that can be closed when there is direct solar radiation. The high radiant heat load when there is direct solar radiation on the glass cannot be overcome by the air conditioning system.

2.4.3. Noise and Vibration

All rotating and reciprocating machinery will be provided with vibration isolation typically comprising of spring and damper mounts.

The mechanical plant shall be designed for the following Noise Criteria levels:

Open plan office space NR40-45

Lobbies, corridors and toilets NR45-50

Car parks dBA60

2.5. Design Approach

2.5.1. Air Conditioning Cooling Outdoor Unit

Separate ODU will be dedicated for each office unit and common area. Space for ODU will be allocated in floor wise.

2.5.2. Air Conditioning FCU

Dedicated fan coil units will be installed in each office ceiling space to condition the office areas. Insulated sheet metal ductwork will connect the FCUs to ceiling diffusers via flexible ducts. Diffusers will be standard square louvered type in tiled ceilings and linear slot type in plaster board ceilings. Air return to each FCU will be via ceiling return plenum. For the future fit out, any enclosed offices that have walls extending to the underside of the slab for acoustic privacy will need to be provided with transfer air ducts in the ceiling space so that return air can be vented back into the general ceiling space. Fan coil units will comprise of low noise, ceiling concealed type units constructed from metal faced polystyrene or closed cell foam insulated. Mechanical components such as fans, cooling coils and air filters will be matched to the load and appropriate for the occupancy of the space. The blower will be three speed types and will be manually controlled to match with the cooling demand of the air conditioned space. Controllers will include on/off, fan speed and set point adjustment and will be located on walls or columns. As per the client requirement, tenants will be allowed to control their fan coil units on demand. The condensate drain from each Fan Coil Unit will drain to one of the drain pipe risers in the chilled water pipe shafts or sanitary shaft.

Common Area Air Conditioning

The lift lobbies and ground floor entrance lobby of the development will be air conditioned using dedicated fan coil units. Fan coil units will be concealed from view in the ceiling spaces and insulated sheet metal duct work will connect to linear slot type ceiling diffusers.

Outside Air

Referring to BNBC 2012, the outside air flow rate for office areas will be 2.5 l/s/person and 0.3 l/sm2 (this is the same as ASHRAE requirement).Pre-cooled outside air units with energy heat recovery system will be located beside the ODU and supply to each floor below via pre-cooled fresh air duct risers. For simplicity and reliability the system will be constant volume; as such no pre-cooled outside air will be available for any floor operating in after hour’s mode.

2.5.3. General Ventilation Systems

General

Fans shall be selected to suit the required duty and ductwork configuration but shall generally be either adjustable pitch vane axial, single width single inlet centrifugal or in-line centrifugal.

Toilet Exhaust

A Central exhaust fan will be provided for the toilets of each zone. A central toilet exhaust fan for office zone will be located on level 25. Make up air will come via the fresh air introduced into the air conditioning system from adjacent office space.

Toilets shall be exhausted at the rate of 25 l/s/sanitary fixture.

Pantry Exhaust

A Central exhaust fan will be provided for the pantry. A central pantry exhaust fan for office zone will be located on level 25. Make up air will come via the supply air from air conditioning system of the office space. Pantry shall be exhausted at the rate of 10 ACH. Both main toilet and pantry exhaust air will be discharge to heat recovery system.

Hub / IT Rooms

These are part of tenant fitout works. However, the base building design provision is that Data Hub / IT rooms will be provided with conditioned air from the tenancy air conditioning system during normal office hours. A ceiling exhaust fan would be provided to maintain air circulation and heat removal from these rooms when the tenancy air conditioning is not operating. A time-clock could be used to turn on the exhaust fans outside the normal operating hours of the tenancy air conditioning.

Car park Ventilation

All basement parking spaces will be mechanically ventilated at an average of 7.6 l/s per m2 of floor area which complies with the Bangladesh Building Code. Car park ventilation system will comprised with main exhaust air fans on ground floor, and draw the exhaust air from all basement floors through an exhaust shaft. Multiple jet fans will be installed in all car park area in both series and parallel array such that the induction of air can take place through these chains of fans. There will not be exhaust air duct installed in the car park as the limitation of the height. Exhaust air will be discharged to outside via a chimney at ground floor. Make-up air system of basements car park will comprised with axial fans. These fans will be installed at high level above drive way, and draw outside air from ground floor via an outdoor air shaft.

The exhaust fans will be operated on high speed for smoke extracting in the event of fire breakout signaled by the fire alarm system. The fans will be provided with a fire resistant, generator backed power supply.

2.5.4. Fire Mode Ventilation Systems

Stair Pressurization System

There are 2 fire escape stairs in this building. Stair No. 1 is start from ground floor to level 25 and stair No. 2 is start from ground floor to Basement4. Natural smoke ventilation system will be provided for above ground floor stairwell. The architect will specify 1.5 m2 external wall opening will be provided on every above ground floors. These openings will either permanently open or energized by fire alarm system Mechanical pressurization system will be provided for underground stairwell to prevent ingress of smoke into the escape path. The system will consist of a dedicated fan, ducted into the stairwell and then discharge the air to single grille on basement 1 floor. Counter weight relief damper will be provided at lowest floor to control pressure within the stair as doors are opened and closed. Upon activation of any fire alarm signal within the building, the pressurization fan will be energized. Each fan will be provided with a fire resistant, generator backed power supply.

2.6. Building Management System

The electrical and mechanical equipment will be controlled and monitored by a comprehensive, state of the art Building Management System incorporating Direct Digital Controls (DDC).

Key characteristics of the BMS will include:

Control and monitoring of VRF AC.

Start, Stop and monitoring of all Core MEP service Equipment. Status of all fans and pumps to be determined from different        
   pressure switches.

Monitor and record electrical energy usage at each office zone as well as electrical characteristics.

Control and monitoring of Car park ventilation systems

Fault and alarm reporting.

Monitoring of pressurization fans

Control and monitoring of Public area, external area lighting

Monitoring of Diesel fuel storage system

Interface with hydraulic services for status and alarm.

Interface with Fire Indicator Panel for status and alarm

Monitoring, Controlling, Optimizing and Reporting for all Core MEP services.

3. Electrical Services Design Report

Monitoring of Transformers, MDBs, kWh metering and Generator Systems

3.1. Introduction

This document has been prepared to outline the design for proposed Tower, a new office tower to be developed in Dhaka, Bangladesh.

3.2. Scope of Works

The electrical services will be appropriate to a good quality office building. All commercial areas will be documented to an open plan layout for future fit out. Services will generally comprise the following:

Electrical power substation

Backbone Power distribution system through BBT

Full Capacity Stand-by power system

Lighting system

General power distribution system

Lightning protection and grounding system

Fire detection and alarm system

PABX System

BTTB Trunk Line

Master antenna television system

24Hrs Surveillance Solution

Security and access control system

Toll based Car Park with Management System

Automatic Rising Bollard in main Entry and Exit.

3.3. Standards and Regulations

The electrical services for the building shall be designed, installed and tested in accordance with the following Standards and Regulations.

a) Bangladesh National Building Code BNBC

b) The Chartered Institute of Building Services Engineers CIBSE

c) International Electro-Technical Commission IEC

d) Illuminating Engineering Society IES

3.4. Load Design Criteria

The electrical services design will be based on the following electrical load densities. The office tenancy electrical densities have been derived from the estimated number of points, it is anticipated will be provided within each tenancy fit out.

Location	Lighting (VA/m2)	Power (VA/m2)	ODU (VA/m2)	FCU Ventilation Fans(VA/m2)	Demand Factor
Parking / Stairs	5	-	-	-	0.8
Toilets	10	-	-	-	0.8
Typ Flr Lift Lobby	11	-	-	-	0.8
Typ Flr Office Lobby	11	-	-	-	0.8
Office Tenancy and Main Gnd Flr Lobby	11	25	103	30	0.8

3.5. Electrical Power Sub-station

The HT supply to the building will be derived from DESCO infrastructure fronting the site at 11kV. An underground feeder will be taken from this supply to medium voltage switchgear located in the substation room on basement level 1 floor and step the voltage down to 400/230 volts for distribution throughout the building. The substation room consists of the high voltage switchboard and the main low voltage switchboard. The high voltage will be regulated by 11kV LVR and switchgear will be VCB, indoor type complete with load break switch for incoming supplies and circuit breakers for outgoing feeds to the transformers. The availability and characteristics of the power supply will be monitored by the BMS. The main electrical room will be 2 hour fire rated. The estimated of demand load is 2500kVA. Then 2 set of 1250kVA transformer will be selected.

3.6. Power Distribution System

Set’s of (As per design Requirement) dry type transformer, suitable for mounting indoors, will be installed on designed location.

The distribution system will be 380/220 volts 3-phase, 4-wire Multiple Earth Neutral (MEN) system. The switchboards will be totally enclosed, floor standing and rated at 380 volts, 3 phases, 50 Hz with fault withstand capacity of 50 kA for 1 second or selected to suitable with transformer capacity. Outgoing sub main protection will be by MCCB. The switchboards will incorporate automatic power factor correction to keep the power factor at or above 0.9 for energy efficiency and to prevent supply authority penalties. Power distribution within the building will be via vertical riser bus ducts with branch circuit breakers connected to floor distribution switchboards located within switch rooms on each floor. Bus ducts will be generally sized based on a maximum 2% volt drop at the electrical distribution board on each level based on the calculated maximum demand of the building. This will allow a maximum volt drop of 3% within each floor for tenant installed cabling systems.1 set of 24-pole panel board will be provided in each floor electrical cupboard for future connection of light and power cabling.

3.6.1. Fire Rated Cabling

Fire resistance cabling will be used for all fire and life safety circuits, inclusive of the following circuits:

a) Car park smoke exhaust fan, Fire pumps

b) Remote emergency lamps

c) All output signal circuits cable for controlling life safety equipment

d) Fire exit stair pressurization system fan

3.6.2. Metering

Digital electrical metering (interfaced with the BMS) will be provided for the following:

a) Each office floor Distribution Board (will record total light, power and AC power consumption for the floor).

 b) Common area lighting and power

3.7. Stand-by Power System

Due to the unreliability of the 11kV mains power network, set/’s of prime rated, diesel engine driven generator shall be provided for the provision of 100% standby power. In the event of a power failure the stand-by generator set will start and supply power to the main switchboard. The generator room is on GF/Basement 1 level and will be provided with acoustic treatment, inlet and outlet air attenuators for reduce radiated noise. The generator exhaust pipe will be fitted with a residential muffler and will discharge at same level. 2set of 1500 liters diesel fuel day tank providing a total capacity of 10 hours, will be provided for the engines inside the fuel storage room.

3.8. Lighting System

3.8.1. Lighting System Design Criteria

In general office and back of house areas, the light level will be designed to comply with Illuminating Engineering Society (IES) Standard.

3.8.2. Emergency & Exit Lighting

Emergency lighting complying with international standards will be provided and comprise of single point, self contained fittings with battery sized for minimum two hour illumination. Emergency lamps will be non maintained type. Illuminated LED type exit signs will be provided throughout stairs, corridors and public areas to facilitate personnel egress in the event of total power failure. Exit lamps will be maintained type.

3.8.3. Lighting Control

Office

All rotary switches will be provided and installed as part of the tenancy fit out works.

Public Areas

Automatic remote switching and control will be provided for all internal public areas, car parking and external lighting via a lighting control system or the BMS system.

3.9. General Power

General power outlets will be provided to suit architectural and interior design philosophy (excluding office tenancy areas which are to be provided as part of the tenancy fit out. General purpose power outlets will be provided to tenancy corridors for cleaning purposes. Weatherproof outlets will be provided to outdoor areas. All power outlets will be provided with the third grounding pin.

3.10. Lightning Protection and Grounding System

The lightning protection system will be of conventional Faraday Cage type to comply with NEC and BNBC. The grounding systems will be provided as follows:

a) Grounding for lightning system

b) Grounding for power system

c) Grounding for pothead and lightning arrester

d) Grounding for communication system

e) The maximum ground resistance will not exceed 5 ohms.

3.11. Fire Detection & Alarm Systems

3.11.1. General

The proposed fire alarm system will enable either manual fire alarms or automatic detection of a fire, and will feature an "intelligent" Detection and Control panel. This will operate in conjunction with an emergency warning and inter-communication system, and will enable fire fighting by a combination of both manual and automatic means. Fire Alarm Graphic Annunciation Panel will be provided at Basement 3 level in BMS room. Fire resistant cabling on non-monitored circuits will be used throughout the building.

3.11.2. Automatic Detection

The primary means of detection will be smoke detectors, although heat detectors will be provided in locations where smoke detectors may generate false alarms. The detectors will be selected and located to comply with NFPA requirements.

A 'fully addressable' fire detection system will be provided in all areas.

3.11.3. Manual Call Points

Manual call points will be provided to enable people to signal the presence of a fire. Manual call points will be provided:-

a) Adjacent to each fire escape stair door

b) At each fire standpipe and hose reel station

Each call point will be ‘fully addressable’ from the central fire detection control panel.

3.11.4. Fire Detection Control Panel

The fire detection control panel will respond to one or more positive signal(s) from either the automatic detection or the manual call points as follows:-

by alerting the security staff

by instigating the fire alarm system within the appropriate zones

by instigating the broadcast of an appropriate message via the Public Address system

by instigating the associated pressurization systems and basement car park exhaust systems

It will also monitor and/or control the following:-

a) emergency warning and intercommunication system

b) fire fighting pumps

c) lifts

d) alarm valves

e) sprinkler system flow switches

f) fire water reserve tank level

g) central AC system shutdown

and finally will be synchronized with the building management system.

The fire detection and control panel will have battery back-up in case of mains power failure.

3.11.5. Emergency Warning and Intercommunication System

The EWIS system, which will be provided throughout the building, will be used to convey appropriate emergency warnings to occupants. Two emergency messages (each in dual language) will be provided on digital memory cards for emergency evacuation system. This will be zoned so that the suitable emergency evacuation announcements will be broadcast in the appropriate areas. All occupied areas, including lifts will be provided with speaker(s). Zoning will be:

a) each floor

b) passenger lifts

c) fire escape stairs

d) basement/carpark

Wiring will be fire resistant to prevent a fire in one area from hampering an evacuation in another area.

3.11.6. Firefighter’s Telephone System

A fire fighter’s telephone outlet will be provided at: each 3rd floor within fire escape stairs, each fire escape stairs entry and substation room to enable direct communication to Fire Command room. This will enable the fire fighters:-

a) to report directly to the Fire Command Center

b) to receive instructions directly from the Fire Command Center

3.12. Telephone and Data System

Remote Subscribing Unit (RSU) will be located at Basement 3 level to receive the incoming telephone service cable from telephone network. The telephone network will be designed based on 1 line per 8m2 of tenancy space (minimum).The MDF room will also be located at Basement 3 level and Sub Patch Panel (SPP) will be located in the electrical & communications riser room on each floor. Telephone and data structured cabling will be provided using Category 6 solution system. Cabling will reticulate from the MPP room to each SPP. Two Telephone Branch Patch panels will be provided for each floor for future distribution of telephone lines as part of the fit out works. Cabling utilizing Category 6 Unshielded Twisted Pair cables will radiate out to all telephone points required and terminate with RJ45 socket outlets.

Data structured cabling will be provided for the management office on Ground level using UTP Category 6 solution. Final cabling utilizing Category 6 Unshielded Twisted Pair cables will radiate out to all data points required and terminate with RJ45 socket outlets Cables will be run in conduit or on cable tray as appropriate to the area of installation.

3.13. Master Antenna Television System

Provision will be made within the main ELV risers for MATV back-bone cabling systems to be supported by local service providers.

Splitter connections will be provided at the communication room / riser for future connection to outlets as part of the tenancy fit out works.

3.14. CCTV System

Colour Pan/Tilt/Zoom and fixed cameras with dome/bullet enclosures will be provided throughout the development in strategic locations such as all entry and exit points, the lifts, car park entrance and lobbies and lift lobbies. All IP cameras will be connected via CAT6 cable run through the false ceiling space to a centralized monitoring at BMS room with sequential switchers. Network Video Recorder (NVR) based storage system will be included for recording of the cameras.

3.15. Security and Access Control System

All fire exit doors will be provided with magnetic door contacts to activate an audible and visible alarm at an annunciator panel to monitor the status of the doors and to detect any unauthorized entry. A panic button housed in a break glass unit will be provided for carpark areas and the lift lobby area on each floor. The panic alarm system will comprise of local audible alarm and an annunciation at the security control panel. Proximity card readers will be provided for building lift access, the ground floor lobby entry/exit doors and the car park gate barrier. A security guard patrol tour system will be provided with check points at strategic locations to monitor the progress of security guards on their route. All alarms will be monitored by the security system head-end in the security control room at ground level.

3.16. Car Park Management System

A proprietary car park management system will be provided to control entrance and exit from the car park and parking within the car park and will comprise of the following principle equipment:

Electric boom gates at entrances and exits from the car park

Proximity card readers at entrances and exits from the car park

Parking bay sensors to determine the number of used and spare parking bays

Directional arrows to direct drivers to empty parking bays

The system will be a proprietary computer based system supplied by an internationally recognized company.

The main equipment will be located within the security control and fire command centre at ground floor.

4. Fire Protection Services Design Report

4.1. Introduction

This document has been prepared to outline the design for the Proposed Tower a new office tower to be developed in Dhaka, Bangladesh.

4.2. Scope of Works

All commercial areas will be documented to an open plan layout for future fit out. Services will generally comprise the following;

Fire water supply system

Automatic sprinkler system

Fire standpipe and hose reel stations

Portable fire extinguishers

Gas System (Clean Agent Fire Extinguisher system)

4.3. Standards and Regulations

The fire protection services will be designed, installed and tested in accordance with the following Standards and Regulations where permitted within the constraints of architectural design.

a) Bangladesh National Building Code BNBC

b) National Fire Protection Association NFPA

c) Factory Mutual FM (for third party certification)

d) Underwriters Laboratory UL (for third party certification)

4.4. Fire Protection System Objectives

The fire protection systems are provided:-

to minimize the risk to occupants from both smoke and fire

to assist occupants to egress the danger area

to minimize the extent of damage to the structure, fabric and contents

The fire protection design will encompass a range of detection, monitoring and fire fighting systems as described in the following sections.

4.5. Fire Water Supply System

The fire water tank and pump room will be located on Designed Location. The capacity of the fire water tank is 200 m3 which is adequate to supply the design fire water demand exceeding the BNBC requirement of 62.5 minutes and also exceeding the NFPA requirement of 60 minutes of fire water rate. This fire water tank and the associated fire pump stations will serve the entire building.

In accordance with BNBC, design pressure requirement for proper operation of sprinkler / standpipe systems in each fire protection zone is a minimum of 310 kPa (45 psi); maximum pressure shall not exceed 2434.1 kPa (350 psi).

4.6. Fire Pump Stations

The fire pump station will be located next to the fire water tank in order to provide flooded suction to the fire pumps. The fire pump station will contain one set diesel fire pump and accessories and one electrical jockey pump. The fire pump will be designed to satisfy the fire water demand rate of 1,892 lpm (500 gpm) conforming to NFPA and Bangladesh Building Code. The fire pump will be automatically operated by pressure switches installed in the fire pump controller upon a decrease in the system pressure from the set point which will occur if a fire hose station, sprinkler or hydrant is utilized. The fire pump will be UL listed / FM approved.

4.7. Automatic Sprinkler System

An automatic sprinkler system will be provided throughout the building and shall be designed according to current NFPA 13 standard. Quick response sprinkler heads will be used in light hazard areas, including office areas. These will activate faster than Standard response heads so that a fire can be more quickly controlled in the early growth phase. Standard response sprinkler heads will be used in ordinary hazard areas (car park area and plant rooms). Wet pipe sprinkler system will be provided in:

All occupiable spaces including car parks and plant rooms except for lift machine room will be provided by pre-action system and 
  electrical plant room will be provide by gas system.

Various sprinkler head types will be used as follows:

Pendant type heads will be used in areas with false ceilings

Upright heads will be used in areas without false ceilings

The site hazard ratings for occupiable spaces in accordance with NFPA 13 are as follows:

‘Ordinary’ hazard for: all plant rooms and storage rooms, car park

‘Light Hazard’ for: office area, corridors, lift lobbies.

The flow rates, system pressures and bulb temperature ratings will be dictated by the requirements of the NFPA 13. Flow switches, supervisory switches, pressure switches and alarm valves will be provided in accordance with NFPA. One wet riser will be provided for each escape stair.

4.8. Fire Hose Cabinets and Standpipe Stations

Fire standpipes will be provided inside each escape stair. At every floor inside each fire exit stair, a 65 mm diameter hose valve will be provided for fireman and trained personnel use. Fire hose valve and hose reel stations will be located according to code requirements, generally adjacent to each emergency exit door and to provide fire hose coverage across the occupied areas. Fire standpipe and hose stations will consist of an automatic fire hose reel with a 1”30 meter long rubber hose complete with nozzle for occupants or untrained personnel use and a 2 ½”hose valve for trained personnel use. At each fire hose station there will also be a fire extinguisher and a fire fighters’ intercom point. External fire department inlet connections for each fire protection pressure zone will be provided at the entrance to the site to allow easy access for the fire brigade.

4.9. Portable Fire Extinguishers

Dry chemical and carbon dioxide extinguishers will be provided in appropriate areas throughout the building. The dry chemical fire extinguishers will be provided in all general areas. A dry chemical extinguisher will be generally provided for every 550m2 (6,000 ft2) of protected area. The normal UL listed rating will be equivalent to 6A-10 B:C. Carbon Dioxide extinguishers will be provided in electrical rooms. The carbon dioxide extinguishers will have at least UL rating of 10B:C. The installation and rating of portable fire extinguishers will be in accordance with NFPA 10.

4.10. Gas System (Clean Agent Fire Extinguisher system)

Total flooding clean agent fire extinguishing systems such as Novec 1230 will be provided for

Electrical substation

Generator room

DATA Room

Each system will be activated by dedicated smoke / heat detectors. It will include the following equipment.

Local control panel with alarm status indication, countdown timer for release of gas, manual  override to abort release and
   immediate manual release of gas

Interlock with room ventilation systems to ensure they are shutdown prior to release of gas

Interface to fire alarm system to raise an alarm when activated.

5. Sanitary Services Design Report

5.1. Introduction

This document has been prepared to outline the design for Proposed Tower a new office tower to be developed in Dhaka, Bangladesh.

5.2. Scope of Works

All commercial areas will be documented to an open plan layout for future tenant fit out. Services will generally

comprise the following;

Potable water storage and supply system

Water treatment, storage and supply system

Sanitary drainage system (sewage, kitchen waste and vent systems)

Wastewater treatment system

Rain water system (Site drainage by civil consultant) Standards and Regulations

5.3. Standards and Regulations

a) Bangladesh National Building Code BNBC

b) American Society of Plumbing Engineers ASPE

c) National Plumbing Code NPC

5.4. Water Supply Source & Demand Design Criteria

Due to the supply pipe from the government water supply authority will be insufficient, Deep tube well water will be used for this project. Water supply will come from a deep well located within the site boundaries and will be delivered to the raw water storage tank located at basement 4 level. Deep well location will be confirmed following on site testing. The deep well water will be treated upto drinking water standard and stored in cold water storage tanks at the same level. The deep well water quality analysis report is required to design the water treatment system.

Design criteria for water demand calculation is:

Office area 45 L/person/day & 8m2/person

Reception / retail area 45 L/person/day & 6.7m2/person

Irrigation water 5 L/m2/day (200m2 allowed)

Based on these design criteria, the daily water consumption is estimated to be 130 m3.

5.5. Domestic Water Storage

As a safeguard against disruption of supply and the resultant consequences, it is proposed to accommodate sufficient storage capacity to allow for interruption.

The tank capacities will be not less than the following details:

Main raw water tank at basement 4 level: with a capacity of 1 day of storage for domestic use.

.

5.6. Cold Water System

5.6.1. General

The system water pressures will be maintained in the range of 1.4 to 3.5 bar (20 to 50 PSI) which is suitable for standard sanitary fixtures and comply with BNBC. Water hammer arrestors will be provided immediately after transfer pumps and in the pipework system. Water outlets will be provided to plant rooms, garbage rooms, car cleaning bays and car parks. Water outlets in public areas will have security heads. Cold water pipes will be PPR or cPVC ( Pipe collars and fire stop seal need to be installed)

Branch pipes on each floor will be PPR or cPVC Tenancy water meters will not be provided.

5.6.2. Pressurized Distribution System

Water will be distributed via a pressurized feed system for controlling the limited pressure level. 3 Duty and 3 standby boosting pumps will lift the cold water from the basement 4 level storage tanks to the risers.

5.7. Sanitary Drain Services System

The sanitary drains shall be designed in accordance with recognized standards, and will incorporate the followings:

Separate Soil and Waste pipes from toilet fixtures and wash basins / pantry sinks

Vents to sewage and kitchen waste systems

Floor drains in wet areas

Condensate drains from air conditioning systems

Wastewater collection

The system will be arranged to minimize the risk of accidental blockage, but will also incorporate readily accessible 'Roding points'. Appropriate water traps will be provided to ensure that the drainage system does not become a source of potentially offensive odors.There will be no drainage point provided in tenancy areas.

Sewage pipe risers will be uPVC; vent and drain risers will be uPVC.

5.8. Central Wastewater Collection

Wastewater from water closets, urinals, hand basin and sink will be collected to wastewater collection tank and deliver to the municipal wastewater treatment plant via septic tank to outside the site. Wastewater flow rate is approximately 21m3/day.

5.10. Rain Water System and Site Drainage System

Building roof drainage will be collected and drained via rain leaders into the site drainage system. The rainfall density design criterion is 100 mm/hour based on Appendix S in BNBC 1993. Rain leaders will be located within the main sanitary shaft or dedicated shafts. Rain leader pipes will be uPVC. Pipe collars and fire stop seal need to be installed. The site drainage design will be by the civil engineer. I understand that a flood control plan study will be undertaken as part of the civil engineer’s scope of works. The site will need to be bounded to minimize risk of flooding in the basement.

6. Vertical Transportation Services Design Report

6.1. Introduction

This document has been prepared to outline the design for the Proposed Tower a new office tower to be developed in Dhaka, Bangladesh.

6.2. Scope of Works

The recommended vertical transportation services will be appropriate to a high quality office building. Services will generally comprise the following;

Passenger lifts

Fire mode provisions

Finishing

Security

6.3. Definitions

The 5 Minute Handling Capacity of a group of lifts is defined as the percentage of the building population within the zone served by those lifts that can be moved in the lifts during a 5 minute two-way traffic peak period assuming the lifts are filled to 80% of their rated capacity. The Average Waiting Time is defined as the average time during a 60 minute peak period that a prospective passenger waits after registering a hall call (or entering the waiting queue if a call has already been registered) until the responding elevator doors begin to open.

6.4. Standards and Regulations

The vertical transportation services to the building will designed, installed and tested in accordance with the following Standards and Regulations

a) Bangladesh National Building Code BNBC

b) European Standards EN81

c) The Chartered Institute of Building Services Engineers CIBSE

d) American Society of Mechanical Engineers Safety Code for Elevators and Escalators ASME, A17.1

6.5. Design Criteria

Our proposal would be for the passenger lift system to be designed to achieve the following criteria. However this will not be possible within the limitations of the spatial provisions that have been provided for the lift shafts:

6.5.1. Passenger Lifts

5 min handling capacity 10 - 12%

Car loading factor 80% maximum

Population density 1 person / 8 m2 (CIBSE standards.)

Car departure interval < 45 secs

Acceleration 0.8 m / sec2 Jerk 1.4 m / sec2

6.5.2. Machine Arrangement

Lifting machines will be machine room less, gearless AC variable voltage variable frequency type.

6.6. Passenger Lifts

Passenger lifts recommended for this project based on our design criteria comprise of the following:

1. Lift Number: P1, P2, P3, P4

            Control: 4 cars destination control

Capacity: 1,050 kg (14 persons)

Speed: 3.5 meters per second

Level Served: B3 – L24

Machine Type: Gearless traction (VVVF)

Handling Capacity: 11%

Average Waiting Time: 40s

2. Lift Number: P1, P2

            Control: Simplex Selective and collective

Capacity: 1,050 kg (14 persons)

Speed: 1.75 meters per second

Level Served: GF – L3

Machine Type: Gearless traction (VVVF)

7. Rain Water Harvesting

Rain water will be collected from roof, ramp and to some extent surface catchment area and will be stored on the lower basement level of tank capacity 60m3.Collected water will be treated and next to store in another reserve tank of capacity 60m3.From that the water will be transferred to the roof separate tank of capacity 10m3.This water will be used for gardening, car wash etc.

8. Waste Water treatment

Waste water will be collected from the wash basin to store on the basement level of tank capacity 50m3. Collected water will be treated and next to store in another reserve tank of capacity 50m3.From that the water will be transferred to the riser in pressurized system to the flash tank.