SECTION EIGHT & NINECONCRETE WORKS

SECTION TWOCONCRETE WORKS

1. GENERAL

This section includes the following:- Concrete formwork and false work.- Concrete reinforcement.- Cast-in-place concrete.- Concrete cures and finishes.

2. REFERENCE STANDARDS, CODES & ACTS:

Conform to the Egyptian Code for Design & Executing Concrete Structures, the Egyptian Standard Specifications (E.S.S), the Uniform Building Code and any applicable acts of any authority having jurisdictions, including occupational health and safety acts and regulations and the following:

1. For Concrete Formwork:1. ACI 117-90 Standard Specification for tolerances for Concrete

Construction & Materials.

2. ACI 301-96 Standard Specifications for Structural Concrete

3. ACI 347-78 (Re-approved 1984) Recommended Practice for Concrete Formwork.

4. ACI 347-94 Guide to Formwork for Concrete.

2. For Concrete Reinforcement:5. ACI 315-92 Details and Detailing of Concrete Reinforcement.

6. ACI 315R-94 Manual of Engineering and Placing Drawings for Reinforced Structures.

7. ACI SP-66 Detailing Manual.8. ACI 318M-95/318RM-95 Building Code Reinforcement

Requirements for Structural Concrete and Commentary.

9. All Standards cited in ACI 318-95 as per Clause 3.8 of ACI 318.

10. ESS 262 hot Rolled Steel Bars for the Reinforcement of Concrete.

11. ESS 1618 Welded Steel Bar Mesh for Concrete Reinforcement

12. ASTM A 82-94 Standard Specification for Steel Wire. Plain for Reinforced Concrete.

13. ASTM A 184-90 Standard Specification for Fabricated Deformed Steel Bar Mats for Concrete Reinforcement.

14. ASTM A 185-94 Standard Specification for Steel Welded Wire Fabric, Plain, for Concrete Reinforcement.

15. ASTM A 496-94 Standard Specification for Steel Wire, Deformed, for Concrete Reinforcement.

16. ASTM A 497-94a Standard Specification for Steel Welded Wire Fabric, Deformed, for Concrete Reinforcement.

17. ASTM A 615-94 A Standard Specification or Deformed and Plain Billet-Steel Bars for Concrete Reinforcement.

18. ASTM A 616-93 Standard Specification for Rail-Steel Deformed and Plain Bars for Reinforcement, including Supplementary Requirements.

19. ASTM A617-93 Standard Specification for Axle-Steel Deformed and Plain Bars for Concrete Reinforcement.

20. ASTM A 706-92b Standard Specification for Low-Alloy Steel Deformed Bars for Concrete Reinforcement.

21. ASTM A 767-90 Standard Specification for Zinc-Coated (Galvanized) Steel Bars for Concrete Reinforcement.

Where there are differences between the specifications and drawings and the codes, standards or acts, the most stringent shall govern.

Standards referenced by the Standards noted above are to apply even if they are not included in the list.

3. For Cast-In-Place Concrete.1. E.S.S. 373/1991 Normal and Quick Setting Portland Cement.

2. E.S.S. 541/1992 Low Temperature Portland Cement.

3. E.S.S. 583/1993 Specification for Sulfate Resistant Cement.

4. E.S.S. 1858 (All Parts) Concrete Testing Methods.

5. E.S.S. 1699/1990 Water Reducing, Accelerating, and Retarding Admixtures.

6. E.S.S. 1947/1991 Method for Taking Concrete Samples.

7. E.S.S. 2149/1992 Medium Temperature Portland Cement.

8. E.S.S. 2421 (All Parts) Testing of Mechanical and Physical Properties of Cement.

9. ACI 117-90 Standard Specifications for Tolerances for Concrete Construction and Materials.

10. ACI 207.4R-93 Cooling and Insulating Systems for Mass Concrete.

11. ACI 211.1-81 Standard Practice for selecting proportions for normal, heavyweight and mass concrete.

12. ACI 224R-90 Control of Cracking in Concrete Structures.

13. ACI 226.3R-97 Use of Fly Ash in Concrete.

14. ACI 301-96 Standard Specifications for Structural Concrete.

15. ACI 304R-85 Guide for Measuring, Mixing, Transporting, and Placing Concrete.

16. ACI 304.3R Heavyweight concrete: Measuring, Mixing, transporting, and placing.

17. ACI 305R-91 Hot Weather Concreting.

18. ACI 308-92 Standard Practice for Curing Concrete.

19. ACI 318-95/318R-95 Building code requirements for structural concrete and commentary.

20. All standards cited in ACI 318-95 as per clause 3.8 of ACI 318.

21. ACI 347R-94 Guide to formwork for concrete.

22. ASTM C 31-91 Standard Practice for Making and Curing Concrete TestSpecimens in the field.

23. ASTMC 33-93 Standard Specification for Concrete Aggregates.

24. ASTM C 39-93a Standard Test Method for Compressive Strength of Cylindrical-Concrete Specimens.

25. ASTM C 42-90 Standard method of Obtaining and Testing Drilled Cores and Sawed Beams of Concrete.

26. ASTM C 94-94 Standard Specification for Ready-Mixed Concrete.

27. ASTMC 109-93 Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (using 50-mm Cube Specimens).

28. ASTM C 14493 Standard Specification for Aggregate for Masonry Mortar.

39. ASTM C 150-94 Standard Specification for Portland Cement.

30. ASTM C 172-90 Standard method of Sampling Freshly Mixed Concrete.

31. ASTM C 192-90a Standard Method of Making and Curing Concrete Test Specimens in the laboratory.

32. ASTM C 260-94 Standard Specification for Air-Entraining Admixtures for Concrete.

33. ASTMC 494-92 Standard Specification for Chemical Admixtures for Concrete.

34. ASTM C 496-90 Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens.

35. ASTM C 595-94a Standard Specification for Blended Hydraulic Cements.

36. ASTM C 618-94a Standard Specification for Fly Ash and Raw or CalcinedNatural Pozzolan for Use as a Mineral Admixture in Portland Cement Concrete.

37. ASTM C 685-94 Standard Specification for Concrete Made by Volumetric Batching and Continuous Mixing.

38. ASTM C 845-90 Standard Specification for expansive Hydraulic Cement.

39. ASTM C 989-93 Standard Specification for Ground Granulated Blast-Furnace Slag for Use in Concrete and Mortars.

40. ASTM C 1017-92 Standard Specification for Chemical Admixtures for Use in Producing Flowing Concrete.

41. ASTM C 1218ε1 Standard Test method for Water-Soluble Chloride in Mortar arid Concrete.

42. ASTM C 1240-93 Standard Specification for Silica Fume for Use in Hydraulic-Cement Concrete and Mortar.

43. ASTM F 1155-87 Standard Test Method for Determining Floor Flatness and Levelness, using the F-Number System.

Where there are differences between the specifications arid drawings and the codes, standards or acts, the most stringent requirement shall govern.

Standards referenced by the Standards noted above are to apply even if they are not included in the list.

3. TOLERANCES

3.1 FOR CONCRETE FORMWORK

1.Tolerances for Concrete Construction and Materials shall conform to all requirements of ACI 117. Standard Specifications for Tolerances for Concrete Construction and Materials

2. Perform forming operations and place hardware so that finished concrete will be within the tolerances set out in ACI and as listed below.

3. Variations in building lines, which result in extension of the building over, lot lines or restriction lines will not be permitted

4. As a minimum, the following tolerances shall be met:

Vertical alignment lines, surfaces and arises 1/1000 times the height above P4 but not more than 150 mm

Lateral alignment MembersIn slabs center line location of openings300 mm or smaller and edge location ofopenings >300 mm

20 mm

20 mm

Level alignment Elevation of top of slab or elevation of formed surfaces before removal of supporting shoringLintels, sills, parapets. horizontal grooves, and other tines exposed to view

20 mm

12 mm

Cross-sectional dimensions: members, such as columns, beams, piers, walls (thickness only), and slabs (thickness only):

300 mm dimension or less

more than 300 mm but not more than 100

more than 1000 mm

+10 mm -5 mmmm+15 mm-10 mm+25 mm-20 mm

Relative alignment Stairs difference in height between adjacent risers

difference in width between adjacent treads3 mm5 mm

Grooves specified width 50 mm or lessspecified width more than 50 mmbut not more than 300 mm

3 mm

5 mm Specified surfaces may slope with respect to the specified plane at a rate not to exceed 10 mm in 3000 mm The offset between adjacent pieces of formwork facing material shall not exceed:

Surface Class A: All exposed concrete except where surface Class C is allowed

3 mm

Surface Class B: All structural elements concealed by applied or suspended architectural finishes

6 mm

Surface Class C: Perimeter foundation walls and mat 12 mm

Surface Class D: Not applicable 25 mm

Openings through members Cross-sectional size of opening -6 mm

+25 mm Location of centerline of opening 12 mmPlacement of embedded items Clearance to reinforcement the greater of the bar diameter or 25mm Vertical alignment. Lateral alignment, and level alignment 25mm 5. These tolerances are acceptable with regards to structural requirements. Inter tolerances with other materials may not be compatible with the above. Revise co-ordinate-interfacing tolerances so that the various elements come to properly.

6. Tolerances shall not be cumulated.

3.2 FOR CONCRETE REINFORCEEMT:1. Perform fabrication, setting, and placing so that completed work will be

within the tolerances set out in ACI 318 and the Egyptian Code for Design and Executing Reinforced Concrete Structure.

2. Tolerances for Concrete Construction and Materials shall conform to all requirements of ACI 117, Standard Specification for Tolerances for Concrete Construction and Materials.

3. For standard fabricating tolerances for bar sizes 4)32 and smaller refer to Figure 2.1(a) of ACI 117.

4. For standard fabricating tolerances for bar sizes larger than (1)32 refer to Figure 2.1(b) of AC1 117.

5. Tolerances shall not permit a reduction in cover except as listed below.

Concrete cover measured perpendicular to concrete surface in direction tolerance• When member size is 300 minor less - 10mm• When member size is over 300 mm - 13 mm• Reduction in cover shall not exceed one4hird specified concrete cover• Reduction in cover to formed soffits shall not exceed 6 mm

6. Clear distance to side forms and resulting concrete surfaces and clear distances to formed and resulting concrete soffits in direction of tolerance

When member size is 100 mm or less + 6 mm - 10 mm

• When member size is over 100 mm but not over 300 mm 10 mm• When member size is over 300 mm but not over 600 mm 13 mm• When member size is over 600 mm 25 mm

7. Distance between reinforcement:• One quarter specified distance not to exceed 25 mm

Providing that distance between reinforcement shall not be less than the greater of the bar diameter or 25 mm for unbundled bars.

• For bundled bars, the distance between bundles shall not be less than the greater of 25 mm, or 1.4 times the individual bar diameter for 2 bar bundles,

1.7 times the individual bar diameter for 3 bar bundles, and 2 times the individual bar diameter for 4 bar bundles

• Spacing of reinforcement, deviation from specified location In slabs and walls other than stirrups and ties 75 mmStirrups: 8% of beam depthTies: 8% of least width of column dimensionHowever, total number of bars shall not be less than that specifiedLongitudinal location of ends and bends of bars:At discontinuous ends of members 25 mmAt other locations 50 mmEmbedment length of bars and length of bar taps:Bar size Φ 32 and smaller - 25 mmBar size larger than Φ 32 - 50 mm

8. These tolerances are acceptable with regard to structural requirements interfacing tolerances may not be compatible with the above.

Review and coordinate interfacing tolerances so that the various elements come together properly.

3.3 FOR CAST IN PLACE CONCRETE:.1 Perform placing operations so that completed work will be within the

tolerances set out in ACI and as listed below:.1 All applicable tolerances listed in the section of Concrete Formwork and

False work shall apply.

.2 Floor finish tolerances as measured in accordance with ASTM E1155-87

.3 Finish tolerances as measured by placing a freestanding (unleveled) 10ft. (3048 mm) straightedge any where on the slab and allowing it to rest upon two high spots within 72 hours after slab concrete placement. The gap at any point between the straightedge and the floor (and between the high spots) shall not exceed:

Classification LimitConventional Bull floated 1/2" (12.5mm)Straight edged 5/16" (8mm)Flat 3/16" (4.7mm)Very flat 1/8" (3.0 mm)

.2 Variations in building lines which result in extension of the building over lot lines or restriction lines will not be permitted.

.3 These tolerances are acceptable with regard to structural requirements. Interfacing tolerances may not be compatible with the above. Review and coordinate interfacing tolerances so that the various elements come together properly.

3.4 FOR CURES AND FINISHES

.1 Tolerances for finished concrete work are to be within permissible deviations tabulated in ACI 347.

4. DESIGN

4.1 CONCRETE FORMWORK AND FALSEWORK

Formwork, False work and Re-shoring.

Design formwork and re-shoring to safely support vertical and lateral loads until they can be supported by the structure. Design formwork for loads and lateral pressures recommended in ACI 347R-94.

The false work design shall be by a qualified Structural Engineer authorized by the Engineer’s Syndicate of Egypt to seal and sign engineering drawings and with demonstrated competence in the design of such temporary construction facilities.

Design and provide shoring and bracing to excavations and underpinning to safely withstand any lateral pressures to which they may be subjected.

The reinforced concrete members designated on the drawings as separation strips are not structurally stable until the strips have been concreted and the concrete has reached at least 70% of the specified strength.

The reinforced concrete members of the ramps and ramp walls between grids X and Z are not structurally stable until the walls have been completed to P1 level, until the ramps are completed, and until the P1 slab has been concreted and until the concrete has reached at least 70% of the specified strength.

The north and east edges of the Lower Ground floor at the drivers quarters is not stable until the Upper Ground floor has been concreted and its concrete has achieved 70% of its design strength.

The edge of slab of the Lower Ground floor generally between grid lines U and V is not stable until the Upper Ground floor framing has been concreted and the concrete has achieved 70% of its design strength.

The separation strips will be concreted after a minimum period of 90 days after the concreting of the areas either side of the strip.

Scaffolding and shoring supporting the edges of these strips is to remain in place until after concreting of the strips and until the strip concrete has achieved 70% of the design strength.

The scaffolding and shoring supporting the slabs and beams hanging from hanger walls at various locations is to remain in place until the concrete of the hanger walls has achieved 70% of the design strength. Several, but not necessarily all, such locations have been shown on the drawings.

Design shoring for these slabs and walls to safely support the total vertical and lateral loads until the walls and slabs are complete and have and have reaches 70% of their specified strength. Design the shoring so that they can be unloaded gradually.

4.2 CONCRETE MIX DESIGN

.1 DESIGN OF MIX

Design the mix in accordance with ACI so that concrete will be homogeneous. uniformly workable, readily placeable into corners and angles of forms and around reinforcement by methods of placing and consolidation employed on the work, but without permitting materials to segregate or excessive free water to collect on the surface. The concrete, when hardened, shall have the qualities specified.

Specified Strength: As called for on drawings. Where walls are integral with columns such as foundation walls cast walls and columns with concrete of the higher specified strength.

Water Cement Ratio, Cement Content, Slump and Air Content: As called for on the drawings. These requirements are for concrete at the point of placing.

Fly Ash: Do not use fly ash in concrete that will be exposed to view.

Use of calcium chloride is not permitted.

.2 HEAVYWEIGHT CONCRETE

Heavyweight concrete is used in the foundation mat below the podium part of the building.

Design mix to meet criteria given at point of discharge into forms. Demonstrate the following by previous performance, and on site

tests:1. Segregation, loss of fines, moisture and the like, will not occur

during methods of conveying and placing to be employed on site.

2. Concrete will not break down or be otherwise adversely affected by high frequency vibration.

3. Concrete shall be finishable with a wood float to a hard surface suitable to receive a screed.

4. Design of concrete in conjunction with water content, placing, finishing, curing and protection to be used on site shall be such as to minimize shrinkage.

5. SUBMITTALS

5.1 CONCRETE FORMWORK AND FALSE WORK

5.1.1 SHOP DRAWINGS FOR FORMWORK, FALSEWORK AND RESHORING

The structural design drawings shall not be reproduced, in whole or in part, for use as shop drawings.

Well in advance of construction, submit to the Consultant drawings showing the complete design of the slab formwork ,falsework and re-shoring systems stamped by a Structural Engineer authorized by the Engineer’s Syndicate of Egypt to seal and sign engineering drawings.

As a minimum, show the following:1) Stripping schedule;2) Sequence for installing re-shoring;3) Number of slabs re-shored at any given time; and formwork details

related to stripping and re-shoring.

● Well in advance of construction; submit to the Consultant drawings showing the complete design of the formwork system to be used for the large transfer girders supporting the pools over the ballroom and over the ballroom elevators. These drawings shall be stamped by a Structural Engineer authorized by the Engineer’s Syndicate of Egypt to seal and sign engineering drawings.

● Also, well in advance of construction, submit to the Consultant drawings showing the complete design of the formwork system to be used for the core walls, columns, and the concrete partition walls above the sixth floor. These drawings shall be stamped by a Structural Engineer authorized by the Engineer’s Syndicate of Egypt to seal and sign engineering drawings.

● Submit a written proposal for review by the Consultant as to how the specified cambers are to be achieved in the field.

5.1.2 OPENING INFORMATION

Submit drawings of the structure showing formed holes, recesses and sleeving required under all Divisions.

5.1.3 SURVEYS Submit surveys showing position of formwork, cast-in-place inserts

and structural elements in their as-built condition.

As a minimum include the following:1) Elevation and location of centerline with respect to grids of all

footings;

2) Location of centerline of all columns with respect to grids at each floor level;

3) Location with respect to grids and horizontal alignment of all concrete walls at all floor levels;

4) Vertical alignment (plumpness) of all columns and walls at all floor levels;

5) Elevation of slab formwork and slabs at all columns, walls, centre of bays, midway between columns along gridlines and at cantilever ends, at points of maximum camber on all floor levels

at the following times- Before concrete placement.- After concrete placement, prior to removal of any

formwork and re-shoring from below.- Between 7 and 14 days after removal of all re-shoring

immediately above and below the subject floor.

6) Location and alignment of edge of slabs with respect to grids at all floor levels;

7) Location and elevation of cast-in-place hardware at all levels;

8) Regular elevation checks of formwork adjacent to separation strips;

9) All surveys submitted must clearly indicate the date when the survey was actually carried out.

5.2 CONCRETE REINFORCEMENT

5.2.1 Shop Drawings for Reinforcement1. The structural drawings shall not be reproduced, in whole or in part, for

use as shop drawings.

2. Prepare reinforcement placing drawings and bar lists taking into account all openings and recesses shown on the architectural, structural, mechanical, electrical, kitchen, waste, laundry, landscape architectural and parking drawings, and on the sleeving shop drawings

3. Completely dimension openings, recesses and sleeves, and relate to suitable grid lines and elevation datum.

4. Prepare placing drawings to a minimum scale of 1:50 in a clear complete manner that will permit placing of reinforcement to be performed without reference to contract drawings.

5. Detail reinforcement in accordance with the contract documents, ACI 315, ACI 315 R, ACI 318 and detailing standards in ACI SP-66.

6. As a minimum, show the following:

Bar sizes, spacing, minimum clearances, location and quantities of reinforcement, welded wire fabric and mechanical splices.

Identification of each bar with a code mark corresponding to the bar lists.

Detail sections to fully illustrate placement of reinforcement at areas such as openings, change of levels, spandrel, stairs and wherever else required.

Large scale detail sections at areas of steel concentrations such as at intersections of beams and columns, column splices or wherever else required.

Placing sequence for reinforcement such as intersections of beams and beams, beams and girders, slabs and beams and within plate flat and two-way slabs.

Minimum clearances between reinforcement and minimum concrete cover protection to reinforcement.

Location and embedment of dowels.

Location, number and type of support accessories, including support bars suitably sized and spaced to rigidly support the weight of reinforcement and construction load.

7. Submit code marks or symbols used on reinforcement of each manufacturer so that Consultant may identify grades and sizes of reinforcement.

5.2.2 Shop drawings for Welding Reinforcement- Submit drawings showing, as a minimum, the following: locations,

elevations and size of welds, welding procedures and techniques, stamped as approved by the AWS.

5.2.3 Shop Drawings for Mechanical Splices- Submit drawings showing, as a minimum, the following: location,

elevations and size of splices, materials and procedures.

5.2.4 Certificates- Provide test data that each size and grade of reinforcement proposed

meets specification requirements. Reinforcement approved for use by the Consultant shall be identified in a manner suitable to the Consultant. Only steel that has been approved will be accepted on jobsite.

- Weldable Reinforcement: Submit reports of chemical compositions and. verification of weldability.

- Submit code marks or symbols used on reinforcement of each manufacturer so that Consultant may identify grades and sizes of reinforcement.

5.2.5 Substitutions- Substitution of different size bars permitted only upon written

approval of Consultant. Requests for substitutions must be supported by calculations and by written proof of compliance with the requirements of the applicable standards. The Consultant reserves the right to reject proposed substitutions.

5.2.6 As-Built Drawings- Mark on a complete set of final reproducible drawings any changes,

additions or deletions that occur during construction as a result of the Contractor’s work, change orders, or for any other reasons.

5.3 CAST-IN-PLACE CONCRETE

.1 SurveysSubmit surveys in accordance with Section 03100, Concrete Formwork and False work.

.2 CertificatesPrior to beginning work and when any change in materials or source of supply is proposed, provide the following certificates prepared by an approved inspection company. The cost of this work shall be borne by the contractor

1. Certification that aggregates and cements propose for the works comply with requirements of specifications and ACI.

2. Certification that compressive strength, water-cement ratio, slump, entrained air content and other specified properties will be met, using the proposed mixes.

3. Give proportions by dry weight of cement, coarse and fine aggregate, type and amount of admixture or air entraining agents, and water-cement ratio, for the mix proposed for each class of concrete. Provide separate mix designs when pump

mixes and mixes containing pea gravel are proposed. Describe in detail on the mix design summary the location(s) where each class of concrete is to be placed in the structure.

4. State for each mix if and how much fly ash or slag is used in lieu of cement.

.3 Well in advance of construction, submit complete details of placing and compaction procedures for heavyweight concrete.

.4 Wet Curing Procedures- At least four weeks prior to implementation in the field, submit a

detailed description of the procedures which will be employed to wet cure the concrete for this structure.

- As a minimum, the procedures shall indicate:• the method of curing which will be used;• the type of materials which will be used;• the duration of curing;• location and number of hoses, sprinklers etc., to ensure 100%

Continuous coverage of the pour; - Submit a 300mm x 300mm sample of each type of material

(absorptive mat, fabric, plastic film, waterproof paper etc.) which will be used to wet cure the concrete.

6. SAMPLES AND ASSISTANCE

6.1 CONCRETE REINFORCEMENT

6.1.1 GENERALSupply samples of all materials and the following, the cost of which shall be paid for by this trade.6.1.2 REINFORCEMENT

- Provide the Consultant access to the reinforcement fabricator’s plant. Inform the Consultant of the period during which fabrication will be undertaken.

- Cut samples of reinforcing steel designated by the Consultant from steel shipped to jobsite. Replace cut reinforcement or splice where permitted by the Consultant.

6.1.3 Cut samples of mechanical splices and welded reinforcement as directed by the Consultant. Replace mechanical splices and welded reinforcement cut out for testing.

6.1.4 Provide templates of column dowels to be butt welded to structural steel base plates under Section 05120.

6.1.5 Support AccessoriesProvide samples of support accessories (chairs, bolsters, spacers) which are intended to be used.

6.2 CAST-IN-PLACE CONCRETE

6.2.1 General Supply samples of all materials and the following, the cost of which shall be paid for by this trade

6.2.3 Concrete Test Specimens- Cooperate in the execution of the concrete specimens testing

program Furnish concrete required, protect specimens against injury and loss, assist in the sampling and storage of specimens.

- Sample concrete, cast specimens and store in accordance with ACI where directed by the Consultant.

- For all Portland cement concrete compressive strength tests, 150 x 150 x 150 cubes shall be used.

- Provide sufficient field curing storage facilities so that specimens representing the various areas can be safety stored in locations representing the curing conditions for those areas. Move the field-cured specimen storage facilities from area to area as the work progresses.

6.2.3 Soil InspectionAssist the geotechnical investigation agency in making their inspections or tests as necessary.

6.3 CURES AND FINISHES

6.3.1 Provide control sample panel size 1.25 x 1.25 m. for plain (Fairface) finish..1 Produce even finish with sheet material (e.g. plywood)

.2 Arrange panels in regular pattern as surface feature unless otherwise shown.

.3 Blow holes less than 10 mm in diameter will be permitted other wise surface is to be free from voids, honeycombing and other large defects.

.4 Variations in color resulting from use of impermeable form lining will be

permitted but surface is to be free from discoloration due to contamination or grout leakage..5 Do not use concrete cover spacers without approval

.6 Surface should be smooth, free from laitance. That should be performed using appropriate tools, to the approval of the Engineer.

6.3.2 Provide control sample min. size 1.25 x 1.25 m for trowelled finish.

7. MATERIALS

7.1 CONCRETE FORMWORK AND FALSE WORK

7.1.1 FORMS.1 Formwork lumber, plywood and wood formwork materials shall conform

to the Egyptian Code requirements and to ACI 347R-94..2 Metal formwork and formwork made of other materials: conform to the

requirements and guidelines given in ACI 347R-94..3 Falsework materials: conform to ACI 347R-94..4 Waterstops in construction joints in foundations mat and in perimeter

foundation walls shall be used according to the Engineer’s instructions and to the manufacturer’s specifications for the approved material.

7.2 CONCRETE REINFORCEMENT:.1 Reinforcing Steel: deformed steel to ASTM A615, A617 and A607, and

to the material specification shown on the drawings. Reinforcement to be welded shall also conform to the material recommendations contained in AWS D1.4. Provide test data proving that each size and grade of reinforcement proposed meets specifications requirements.

.2 Welded Steel Wire Fabric: conforming to ASTM A185 and A 497. Provide in flat sheets only.

.3 Chairs, balusters, bar supports, spacers: to ACI 315 and 318. In the case of concrete exposed to view or weather the accessories shall such that no metal is permitted to come closer than 40mm from face and 50 mm from a trowelled surface. Use pre-cast concrete supports for exposed concrete beams and soffits and concrete cast against soil.

.4 Special support bars and system for top steel of foundation bars mat: Design and provide adequate support for top reinforcement of foundation mat. Ensure that weight is well distributed so as t not damage the waterproofing below the mat. Provide adequate bracing in all directions

against lateral movement of top mat, however caused, but in particular as can arise from the forces generated by hoses used in placing concrete by pumping.

.5 Support accessories for suspended parking garage slabs: An approved plastic or non-corroding type of chair, blaster or spacer of sufficient strengths to rigidly support the weight of reinforcement and construction loads. Do not use plastic coated or plastic tipped steel chairs.

.6 Mechanical Tension Splices: of approved type.

.7 Mechanical Compression Splices: of approved type.

.8 Shear Reinforcement in Typical Floors: of approved type.

7.3 CONCRETE CAST-IN-PLACE CONCRETE

7.3.1 CEMENT:Ordinary Portland Cement shall be used for casting all plain and reinforced concrete elements of different building, and shall comply with BS 12.

The Contractor shall show that the quantity and quality of required cement can be attained and maintained throughout the construction period Representative samples of the proposed cement shall be taken and forwarded to an independent accepted laboratory for analysis before the source is accepted. Having obtained acceptance, the Contractor shall not change the agreed arrangements without the acceptance of the Engineer. Each consignment of cement shall be accompanied by a certificate showing the place and date of manufacture and the results of standard tests earned out on each production batch included in the consignment. The standard physical and chemical tests shall comprise those specified in BS standards and herein, including the full chemical composition, SiO2, A12O, Fe2O3 , MgO, SO3 , Na2O, K2O, insoluble residue and loss on ignition.

Additionally, the Contractor shall make arrangements with an authorized local specialized laboratory for carrying out the standard physical and chemical tests on each consignment of cement upon arrival, and also at monthly intervals during storage. If cement remains in storage for longer than 3 months or is at risk of contamination by damp, this regular testing regime shall be supplemented using the loss on ignition test. Cement which fails to satisfy the test requirements shall be rejected and removed outside the site.

7.3.2 AGGREGATES:Aggregates shall conform to BS 882 and shall be tested in accordance with BS 812. The definitions of BS 882 shall apply. Coarse aggregate to withstand the specific environmental conditions shall be used. The Contractor shall obtain acceptance of the proposed aggregate sources, and shall select suitable samples of fine and coarse aggregate for specified testing before obtaining the aggregate. Laboratory tests shall be made at regular intervals to confirm the suitability of the aggregate. The acid-soluble sulphate (SO3) level in the combined aggregate as a percentage by weight shall not exceed 0.4%. The acid-soluble chloride ion (CI) in the combined aggregate as a percentage by weight shall not exceed 0.02% according to Egyptian Code of Practice for Reinforced Concrete No. 464/89.

The Contractor shall wash all fine and coarse aggregates by the use of an efficient up-to-date washing system accepted by the Engineer.

7.3.3 FINE AGGREGATEAs defined in BS 882, fine aggregate shall mainly pass through a 5 mm BS test sieve and shall be graded so that when mixed with the coarse aggregate and cement, a concrete of maximum density is produced. The grading shall be within the limits prescribed for sand in BS 882 Table 4 (C or M grading), or otherwise specified or accepted by the Engineer.

Fine aggregate shall be free of injurious amounts of organic impurities and deleterious substances Beach sand shall not be used in concrete or mortar

The amount of material passing a 75 micron BS 410 fine test sieve when tested in accordance with BS 812 Part I shall not exceed 3% by weight.

When subjected to five cycles of the soundness test specified in ASTM C88, fine aggregate shall show a weight loss not exceeding 10% when magnesium sulphate solution is used

7.3.4 COARSE AGGREGATEAs defined in BS 882, coarse aggregate shall mainly be retained on 5mm BS test sieve, the grading shall be within the limits prescribed for aggregate in BS 882. Table 3, or as otherwise specified or accepted by the Engineer, so that when mixed with the accepted fine aggregate and cement, workable concrete of maximum density s produced The densities of the different classes of concrete shall be as accepted after tests have been carried out on Site. Coarse aggregates shall be of a nominal maximum size not exceeding 20 mm. The amount of material passing a 75 micron BS 410 fine test sieve when tested in accordance with BS 812 Part 1 (decondition method) shall

not exceed 1% by weight.When subjected to five cycles of the soundness test specified in ASTM C88, coarse aggregate shall not show a weight loss exceeding 10% when Magnesium sulphate solution is used. Flaky and elongated aggregate shall not be permitted.

7.3.5 QUALITY AND TESTING OF AGGREGATESAggregate shall be free from dust, clay, loam and soft, shaley, clayey or decomposed stone, organic matter and other impurities and shall be hard and dense, to satisfy the properties and limits specified herein Aggregate shall not contain any matter which, in the opinion of the Engineer, is likely to undergo disruptive expansive reactions with alkalis in the mix or likely to otherwise affect the long term durability of the concrete. Reference is to be made to BS 8110 and to the Building Research Establishment Digest 330, 1988 (superseding Digest 258 referred to in BS 8110) for guidance in reducing the risk of deleterious Alkali-Silica reaction to the absolute minimum.

As precautionary measures against deleterious alkali-silica reactions, the contractor shall send samples of the aggregates proposed to be used to an accepted specialized laboratory for petrographic analysis and alkali-aggregate reactivity tests, including testing by chemical methods described in ASTM C289 or rock cylinder method in ASTM C586.

The following tests shall be conducted to assess the suitability of aggregates:1. Grading2. Magnesium sulphate soundness3. Specific gravity4. Water absorption5. Clay, silt and dust content6. Organic impurities7. Sulphate and chloride content8. Crushing value, alternatively 10% fines value or impact value as accepted.9. Elongation and flakiness10. Potential alkali reactivity11. Los Angeles abrasion test12. Moisture content13. Petrographic analysis

The frequency of tests (1) to (13) shall he in accordance with Table (1), or as otherwise specified more frequently by the Engineer The tests shall be carried

out in accordance with British Standards and/or ASTM Standards, as appropriate, and the results shall comply with the limits given therein, or as otherwise stated herein.

Grading test shall be carried out daily or per 200m³ of concrete whichever is more frequent, when concrete is being produced on a regular basis, or beforehand when production is irregular.

The combined grading of aggregate shall be constant The percentage passing any sieve size, as determined by accepted trial mixes, shall be the target grading for all concrete of that type. The combined grading of the works concrete shall not vary on any sieve from that target by more than 4.0% of the total quantity of fine and coarse aggregate if the estimated or measured combined grading of the permanent works concrete does not meet this requirement, a new trial mix shall be prepared for acceptance.

Table (1) – Frequency of Tests for Aggregates

No Test Coarse or Fine Aggregate

1 Grading 1/ day or 1/200 m³whichever is more frequent

2 Magnesium sulphate soundness Initial only or when changing the source

3 Specific gravity 1/ week or 1/1000 m³whichever is more frequent

4 Water absorption 1/ week or 1/1000 m³whichever is more frequent

5 Clay, silt and dust content 1/ day or 1/200 m³whichever is more frequent

6 Organic impurities 1/ week or 1/1000 m³whichever is more frequent

7 Sulphate and chloride content 1/ week or 1/1000 m³whichever is more frequent

8* Crushing value; alternatively 10%fines value or impact value

1/ week or 1/1000 m³whichever is more frequent

9* Elongation and flakiness 1/ day or 1/200 m³whichever is more frequent

10 Potential alkali reactivity Initial only or when changing the source

11* Los Angeles abrasion test 1/ week or 1/1000 m³whichever is more frequent

12 Moisture content 2 / day13 Petrographic analysis Initial only or

when changing the source.

* For coarse aggregate only.

7.3.6 WATERThe Contractor shall make his own arrangements and obtain acceptance for the provision of fresh water for the manufacture and curing of concrete. Water to be used for washing coarse and fine aggregates and mixing and curing concrete and mortar shall be fresh and free from sediment and dissolved or suspended matter which may be harmful, and shall comply with the requirements of BS 3148.

Water samples from the intended source of supply shall be taken for analysis before any concrete work is commenced, and at intervals throughout the duration of the Works as specified by the Engineer If the samples are unacceptable, the Contractor shall either change to a new supply or take steps to improve the existing source as accepted

The sulphates (SO3) content shall not exceed 300 mg/L and the chloride ion content shall not exceed 500 mg/L. Tests to establish the contents shall be carried out at weekly intervals. These limits shall be subjected to the overall limit given for the concrete as mixed.

7.3.7 ADMIXTURESLow water-cement ratios required by the Specifications may be met with the use of proven water-reducing admixtures in liquid form complying with BS 5075. Where approved or specified, admixture(s) shall be used as means of

a. Achieving workability with the lowest appropriate water-cement ratio in order to achieve durability.b. Controlling and retarding setting.c. Reducing bleeding and associated plastic settlement and cracking.

Set-retarding and water-reducing admixtures shall normally’ be limited to those based on lignosulphonate or sodium naphthalene sulphate. Air entraining agents shall be based on neutralized vinsol or other resins. Admixtures other than those specified herein shall only’ be used provided that the prior acceptance of the Engineer has been obtained and any’ information or test results required by him have been provided and are to his satisfaction. Admixtures containing chlorides or other corrosive agents shall not be used.

In the event of admixtures being used, the concrete tests described in the Specifications shall be incorporated to ensure the specified strengths are achieved and comparison shall be made with concrete manufactured without the admixture to prove that the density has not been reduced and the other characteristics have not been adversely affected If air entraining agents are

used, the density shall not be reduced by more than 5% Not more than one admixture may be used in any one concrete mix

When admixtures are used in the Works, very strict control shall be maintained to ensure that the correct quantity of admixture is used at all times. The equipment to be used for dispensing and the method of incorporating the admixture in the concrete shall he to the acceptance of the Engineer. The dispensing unit shall be translucent such that the operator can see the discharge of the admixture.

Admixtures manufactured by PROKEM, 33 Safya Zaghloul St., Alexandria; Egypt Tel: 03-48 75477/4803303, Fax: 03-4803303, as follows:

.1 KEMFLOW RR; is a retarding and water reducing admixture according to B.S.5075 part 1 or ASTM C494, type A & D or Egyptian Specification No.1899/1990, with low sensitivity to warm weather.

.2 KEMFLOW X-R; is a water reducing and retarding admixture complies with BS5075 and ASTM C494-81 type A+B & D or Egyptian Standard Specification No. 1899/1990.

.3 KEMFLOW SUPER F, is a super plasiticizer high range water reducing admixture complies with ASTM C494 type F and to BS 5075 or Egyptian Standard Specification No. 1899 / 1990. .4 KEMFLOW SUPER G, is a high range water reducing and set retarding admixture complies with BS 5075 and ASTM MC 494 type G and to Egyptian Standard Specification No. 1899 / 1990.

.5 KEMPROOF C, is an integral liquid waterproofed complies with BS 5075, ASTM C 494 type A and Egyptian Standards Specification No. 1899/1990.

.6 PROFIBER, is an admixture to concrete as a secondary reinforcement , to reduce shrinkage and settlement cracks and to increase resistance to impact and to improve flexural and tensile strengths. The fibers could be poly propylene or alkali resistant fiber glass. It complies with B.S 8204-1:1999, 5328-2:1991 and ASTM-C827-87.

7.3.8 MOULD RELEASE AGENT

.7 KEMREL, is a chemical mould release, water-based emulsion to provide quick, clean, and easy stripping of moulds to ensure fair-faced and stain-free concrete.

.7 KEMREL O, is a chemical release agent based on mineral oils and specially formulated to give an easy release of formwork and a high quality surface-finish to concrete.

7.3.9 CURING COMPOUNDS

.8 KEMCURE, is a liquid membrane-forming compound complies with ASTMC 309-81 type 1 class A.

7.3.10 GROUTS BENEATH BASE PLATES

.9 CHEMGROUT HD, is a non-shrink flowable grout having a compressive strength at 28 days of at least 60 MPa. It contains no ferrous components.

.10 CHEMGROUT EP, is a solvent-free epoxy grout having a compressive strength at 7 days of at least 90 Mpa.

.11 CHEMGROUT AID F, is a thixotropic stabilizer of concrete and grouts to be used in running water conditions to prevent cement wash-out.

.12 CHEMGROUT AID, is a powder admixture for cement grouts and concrete, combining a plasticizing agent and a gas producing expansion medium. The expansion medium counteracts the natural settlement and plastic shrinkage of the grout and aids stability and cohesion. Sufficient restrained expansion is developed to ensure a high degree of interfacial contact.

8. EXECUTION:

8.1 FORMWORK:

8.1.1 GENERAL.1 Erect, support, brace, and maintain formwork to safely support vertical and lateral loads until they can be supported by the structure..2 All false work erection shall be supervised by the Structural Engineer responsible for its design.

8.1.2 CONSTRUCTION.1 Where shown, camber formwork such that hardened concrete, prior to

stripping of forms, is cambered as shown. Maintain beam depth and slab thickness from cambered surface.

.2 Camber slabs and beams 1 in 500 of span unless shown otherwise.

.3 Mark building, grid or other lines on forms to permit the accurate positioning of reinforcing steel.

.4 Construct templates and supports to rigidly fix reinforcing dowels in the forms prior to concreting.

.5 Provide suitable markers to indicate the location and configuration of continuing concrete members so that dowels can be positioned accurately in relation to their position in the continuing members.

.6 Set anchor bolts, templates, steel connection units, hardware, or other inserts into the forms and secure them rigidly so that they do not become displaced during concreting. Set and secure these items to the tolerances specified and required in the appropriate Divisions.

8.1.3 SLEEVES, CHASES AND FORMED OPENINGS.1 Form sleeves, chases and openings except where such items are specified

to be formed or sleeved by the appropriate trade.

.2 All openings, sleeves, chases are not necessarily shown on the structural drawings nor are their sizes or locations shown. Refer to architectural, mechanical, electrical, kitchen, laundry, waste, vertical transportation, landscape architectural, parking, and exterior lighting drawings and specifications for openings and sleeving requirements not shown, located and dimensioned on the structural drawings.

.3 No sleeves, chases and openings through structural members shall be. formed without-the Consultants approval.

8.1.4 EXPOSED CONCRETE FORMS.1 Make joints of forms sufficiently tight to prevent leakage of concrete

fines at corners of exposed beams, walls and columns or at the corners of exposed edges of slabs, and other concrete exposed to view in the finished building.

.2 Provide 25 mm chamfer strips at all exposed edges of concrete and 18 mm

v-joints at control joints.

.3 Form panels for exposed concrete may be reused 3 times, providing the tie holes are reused and panels are not damaged in a way that will cause visual defects.

8.1. 5 STRIPPING OF FORMS AND RESHORING.1 Where forms are stripped from horizontal or sloping members before

concrete has reached its specified 28 day strength, reshore the members so that they can safely support their own load plus construction loads. In addition, ensure that the stripped member is of sufficient strength to safely carry its own weight over the area stripped out at any instant, together with any superimposed construction loads.

.2 As a minimum conform to requirements of ACI 347R-94 and the following:

.1 Reshoring in the lower storeys shall be capable of safely carrying the full weight of the concrete and formwork posted to them prior to the removal of the first storey of shoring supported by the ground or slab on grade.

.2 After reshoring is removed from the first storey, the design and provision of reshoring may be based on the assumption that each shored or reshored flexural member shares load in relation to its achieved strength, provided the flexural member has attained at least 70% of its specified 28 day strength.

.3 Install reshoring so that it is supported on members which can safety support the reshore load.

.4 As a guide, under specified curing conditions, 70% of the 28 day strength should be attained 7 days after concreting in normal weather.

.5 Base decision to strip forms upon satisfactory results of 7 day concrete cube tests and on site curing conditions.

.6 Stripping and reshoring shall proceed simultaneously so as not to leave an area greater than 9 sq.m-. unsupported by either formwork or reshoring at any instant. Install reshoring tight to construction above and below so that it will not significantly shorten under toad, .but take care

not to pre-load the construction below or raise the construction above by over-tightening.

.7 Maintain reshoring or formwork in place for a minimum of 28 days or for such longer time as may be required to ensure that the concrete has reached its specified 28 day strength.

.8 Do not strip within one and a half bays of a construction joint until new concrete beyond the construction joint has reached 70% of its specified 28 day strength.

.9 Provide and install adequate shoring to safely support horizontal or inclined members after the 28 day specified strength is achieved where superimposed loads exceed design loads.

.10 Side forms for vertical members may be stripped as soon as the concrete is sufficiently strong to stand unsupported and safely resist imposed loads.

8.1.6 CONSTRUCTION JOINTS

.1 Obtain approval from the Consultant for location and details of construction joints not shown.

8.1.7 SEPARATION STRIPS

.1 Construct strips at the locations indicated and in accordance with the details shown.

.2 Separation strips are to be concrete no sooner than 90 days after the last placing of concrete in adjoining areas.

8.1.8 WATER STORAGE TANKS

.1 Conform with the requirements of this section and the following for the construction of the walls and base slabs of the water storage tanks.

.2 Provide waterstops of the type specified herein embedded in the concrete across joints as shown on the drawings and fully continuous for the extent of the joint. Conform to printed instructions of manufacturer of the waterstop. Take suitable precautions and means to support and protect the waterstops during the progress of the work and repair or replace any waterstop damage. Store waterstops in the shade so as to permit free

circulation of air around the waterstop material In the event any waterstop is installed in the concrete on one side of a joint and will remain unembedded in concrete on the opposite side of the joint for more than 2 days, take suitable precautions to shade and protect the exposed waterstop from the direct rays of the sun during the entire exposure and until the waterstop is embedded in the concrete on both sides of the joint.

.3 Splice waterstops by heat sealing the adjacent waterstop sections in accordance with the manufacturer’s printed recommendations: It is required that:

.1 The material not be damaged by heat sealing.

.2 The splices have a tensile strength of not less than 60 % of the unspliced materials tensile strength.

.3 The continuity of the waterstop ribs and of its tubular centre axis be maintained.

.4 Only butt joints of the ends of two identical waterstop sections may be made while the material is in place in the forms.

.5 Provide factory made prefabricated waterstop joints where more than 2 ends are to be jointed together and including flat L, T and X intersections, and all joints which involve an angle cut, alignment change, or the joining of two dissimilar waterstop sections allowing not less than 450 mm long strips of waterstop material beyond the joint. Upon being inspected and reviewed install such prefabricated waterstop joint assemblies in the forms and butt weld the ends of the 450 mm strips to the straight run portions of waterstop in place in the forms.

.6 Setting waterstops: In order to eliminate faulty installation that may result in joint leakage, take care in the correct positioning of the waterstops during installation. Support the waterstops during the progress of . the work to ensure the proper embedment in the concrete. Equally divide the symmetrical halves of the waterstops between the concrete pours at the joints. The centre axis of the waterstops shall coincide with the joint openings at the plane of installation of the waterstop. Ensure maximum density and imperviousness of the concrete by thoroughly working it in the vicinity of all joints.

.7 Placement of concrete around waterstops: Take care in placing concrete around waterstops by careful working, routing, and vibrating to ensure

that all air and rock pockets have been eliminated.

.8 Inspect all field joints in waterstops for misalignment, bubbles, inadequate bond, porosity, cracks, offsets, and other defects which would reduce the potential resistance of the material to water pressure at any point. Replace defective joints with material which will pass said inspection.

.9 Remove faulty material from the site.

.10 The following defects represent a partial list of defects which shall be grounds for rejection:

.1 Offsets at joints greater than 1 mm or 15 % of material thickness at any joint, whichever is less.

.2 Exterior crack at welded joint in outer surface due to incomplete bond, which is deeper than 1 mm or 15 % of material thickness at any joint, whichever is less.

.3 Any combination of offset or exterior crack which will result in a net reduction in the cross-section of the waterstop in excess of 1 mm or 15 % of material thickness at any joint, whichever is less.

.4 Misalignment of joint which results in a longitudinal misalignment of the waterstop in excess of 12 mm in 3 m.

.5 Porosity in the welded joint as evidenced by visual inspection.

.6 Bubbles or inadequate bonding which can be detected with a pen-knife test. (If, while prodding the entire joint on each side with the point of a pen-knife, the knife breaks through the outer portions of the weld into a bubble, the joint shall be considered defective).

.7 Nail holes in the middle 2/3of the waterstop material.

.8 Dirt, oil, grease, paint or other foreign material on the waterstop.

8.1.9 SEPARATION STRIPS

.1 Maintain bays containing separation strips and each adjacent bay fully formed and shored until the strip is complete, and has reached its 28-day specified strength. Ensure that the forms and shoring are designed so that no settlement of the forms occurs during the period that the strip is open.

8.1.10 QUALITY CONTROL

.1 Implement a system of quality control to ensure that the minimum standards specified herein are attained.

2 Bring to the attention of the Consultant any defects in the work or departures from the Contract Documents which may occur during construction. The Consultant will decide upon corrective Action and give recommendations in writing.

3 The Consultant’s general review during construction and inspection and testing by Independent Inspection and Testing Companies reporting to the Consultant are both undertaken to inform the Client of the Contractor’s performance and shall in no way augment the Contractor’s quality control or relieve the Contractor of contractual responsibility.

8.1.11 NOTIFICATION

.1 Prior to commencing significant segments of the work, give the Consultant and lndependent Inspection and Testing Companies appropriate notification so as to afford them reasonable opportunity to review the work. Failure to meet This requirement may be cause for the Consultant to classify the work as defective.

8.1.12 INSPECTION AND TESTING

.1 The Project Manager will appoint Independent Inspection and Testing Companies to make inspections or perform tests as the Consultant directs. The Independent Inspection and Testing Companies shall be responsible only to the Consultant, and shall make only such inspections or tests as the Consultant may direct.

8.1.13 DEFECTIVE MATERIALS AND WORK

.1 Where evidence exists that defective work has occurred or that work has been carried out incorporating defective materials, the Consultant may have tests, inspections or surveys performed, analytical calculations of structural strength, made and the like, in order to help determine whether the work must be corrected or replaced.

.2 All testing shall be conducted in accordance with the requirements of the relevant Egyptian, ACI and ASTM Standards, except where this would, in the Consultant’s opinion, cause undue delay or give results not representative of the rejected material in place. In this case, the tests shall be conducted in accordance with the standards given by the Consultant.

.3 Materials or work, which fail to meet specified requirements, may be rejected by the Consultant whenever found at any time prior to final acceptance of the work regardless of previous inspection. If rejected, defective materials or work shall be promptly removed and replaced or repaired to the satisfaction of the Consultant, at no expense to the Owner.

8.2 CONCRETE REINFORCEMENT

8.2.1 FABRICATION

.1 Fabricate reinforcement in accordance with ACI 315, ACI 31 5R and the ACI Detailing Manual, ACI SP-66.

.2 Identify with a tag each bundle of bars with a code mark corresponding to that appearing on the bar list.

.3 Bend reinforcement once only and at room temperature, without the use of heat or torch. Do not straighten or re-bend reinforcement. Do not use bars with kinks or bends not shown on the drawings.

.4 Replace bars which develop cracks or splits.

8.2.2 PLACING

.1 Prior to concreting, accurately place reinforcement, support and secure against displacement, as indicated on reviewed placing drawings and in accordance with ACI 315, ACI 315R and the AGI Detailing Manual, ACI SP-66. Tack welding of reinforcement to secure in place will not be permitted.

.2 Set column anchor bolts and wall dowels prior to concreting with wooden templates or other approved means.

.3 Do not drive or force reinforcement into fresh concrete.

.4 Secure reinforcement in walls using sufficient spacers on each face to maintain the requisite distance between reinforcement and column or wall face and so that vertical bars are plumb.

.5 Where toppings are placed on waterproof membranes, vapour barriers and the like, prevent reinforcement or tie wire contacting these items.

.6 Pre-assemble column and beam cages as necessary. Do not ‘spring’ or bend ties and stirrups in order to place longitudinal reinforcement.

.7 Provide splices only where shown on the Contract Drawings. No other splices will be permitted without written approval of the Consultant.

8.2.3 FIELD BENDING

.1 Do not field bend reinforcement except where indicated or authorized in writing by Consultant.

.2 When field bending is authorized, bend without heat, applying a slow and steady pressure until desired configuration is achieved.

.3 Replace bars which develop cracks or splits.

8.2.4 WELDED WIRE FABRIC

1 Where no reinforcement is shown on drawings, provide, as a minimum, 152 x 152 MW18.7/ MW18.7 or equivalent welded wire fabric at mid-depth in slabs on grade or walks or toppings 60 mm in thickness or greater, unless noted otherwise on drawings.

2 Lap ends and sides of fabric not less than 300 mm.

8.2.5 CONSTRUCTION JOINTS

.1 Obtain written approval from the Consultant for details of construction joints not shown.

.2 Continue reinforcement through the joint in its normal position. Add additional reinforcement across the joint as shown or directed.

.3 Mechanical Splicing of Reinforcement

.1 Tension Splices

• Provide mechanical tension splices at locations indicated.

• Splices shall develop in tension at least 125 per cent of the specified yield strength of the reinforcement being spliced or of smaller bar if the bars spliced are of different sizes.

• In each concrete member unless otherwise indicated, splice not more than one third of the bars at any one location. Distance between adjacent splice location shall be not less than 450 mm.

• Install mechanical splices in strict accordance with the manufacturer’s requirements.

.2 Compression Splices

• Provide compression splices at locations indicated.

• Splices shall develop the ultimate compressive strength of the reinforcing bars spliced.

• Accurately saw cut the end bearing surfaces of all bars to be spliced 90 degrees to the axis of the bar with a tolerance of 2 degrees.

• In setting the bars, rotate until the angle between bearing surfaces is at a minimum.

• In each concrete member, splice not more than one third of the bars at any one level. Distance between adjacent splice levels shall be not less than 750 mm.

8.2.6 QUALITY CONTROL

.1 Provide a system of quality control to ensure that the minimum standards specified herein are attained.

.2 Bring to the attention of Consultant any defects in the work or departures from the Contract Documents which may occur during Construction. The Consultant will decide upon corrective action and give recommendations in writing.

.3 The Consultant’s general review during construction and inspection and testing by Independent Inspection and Testing Companies reporting to the Consultant are both undertaken to inform the Client and the Project Manager of the Contractor’s performance and shall in no way be used to augment the Contractor’s quality control or relieve the Contractor of quality control and contractual responsibility.

8.2.7 NOTI FICATION

.1 Prior to commencing significant segments of the work, give the Consultant and Independent Inspection and Testing Companies appropriate notification so as to afford them reasonable opportunity to review the work. Failure to meet this requirement may be cause for the Consultant to classify the work as defective.

8.2.8 INSPECTION AND TESTING

.1 Appointment of Independent Inspection and Testing Companies.

.1 The Project Manager will appoint the Independent Inspection and Testing Company to make inspections or perform tests as the Consultant requests. The Independent Inspection and Testing Company shall be responsible only to the Consultant, and shall make only such inspections or tests as the Consultant may direct.

.2 When defects are revealed, the Consultant may request, at the Contractor’s expense, additional inspection or testing to ascertain the full extent of the defect.

.2 Tests on Reinforcing Steel by Independent inspection and Testing Companies.

.1 A series of specimens for each grade and size of reinforcing steel contained in any 100 tonnes of steel shipped may be tested. A series of tests will include two bars for each test required of each size and grade of steel used. Reinforcing steel tests will be made in accordance with ASTM Standards.

.2 Non-destructive tests may be made on welded reinforcement.

.3 Tension tests to destruction may be performed on approximately 5% of mechanical splices.

8.2.9 DEFECTIVE MATERIALS AND WORK

.1 Where evidence exists that defective work has occurred or that work has been carried out incorporating defective materials, the Consultant may have tests, inspections or surveys performed, analytical calculations of structural strength made, and the like, in order to help determine whether the work must be replaced.

.2 All testing shall be conducted in accordance with the requirements of the relevant Egyptian and ASTM Standards except where this would, in the Consultant’s opinion, cause undue delay or give results not representative of the rejected material in place. In this case, the tests shall be conducted in accordance with the standards given by the Consultant.

.3Materials or work which fail to meet specified requirements may be rejected by the Consultant whenever found at any time prior to final acceptance of the work regardless of previous inspection, If rejected, defective materials or work shall be promptly removed and replaced or repaired to the satisfaction of the Consultant, at no expense to the Owner.

8.3 CAST-IN-PLACE CONCRETE 8.3.1 PLACING CONCRETE

.1 Conform to the requirements of ACI 318 and ACI 304R and the following:

.1 Immediately before placing concrete, clean forms and reinforcement of foreign matter.

2 During hot weather conditions, do not use concrete mixed more than 1 hour after introduction of mixing water or 1½ hours during other periods, unless the concrete mix has been designed with appropriate admixtures to allow longer time before placing.

.3 Allow 24 hours minimum to elapse after placing concrete in columns, piers or walls before placing concrete in beams or slabs supported thereon.

.4 Remove concrete spilled onto forms around heisting equipment before depositing concrete in these areas.

.2 Pumping Concrete.1 Pumping or pneumatic placing of concrete shall only be used if

the velocity of discharge is reduced to a point where no separation or scattering of the concrete occurs, and the consistency of the mix has been designed to allow such a system with no adverse effects on the quality of concrete.

8.3.2 CURING CONCRETE

.1 General

.1 Cure all concrete in accordance with ACI 318 and ACI 308, except as specified herein.

.2 Wet Curing

.1 The following provisions apply to the foundation mat, the water tanks, the pool support girders and beams as well as the pool slabs.

.2 Basic Curing Period - the concrete shall be protected from premature drying and extremes of temperatures, and shall be wet for a period of three (3) consecutive days. Wet curing shall commence immediately after placement and finishing of the concrete.

.3 Additional Curing for Durability - Immediately following the Basic Curing Period, continue to wet cure the concrete for an additional four (4) consecutive days or until the concrete reaches 70% of its 28 day compressive strength, whichever is greater.

.4 Wet curing is to be achieved using one or more of the techniques outlined in ACI 318 and ACI 308.

.5 If an absorptive mat or fabric material is used, it is imperative that it be kept continuously wet, by means of sprinklers, soaker hoses or other acceptable means.

.6 The use of curing compounds will not be permitted in these areas unless written approval is received from the Design Consultant.

8.3.3 PROTECTION

.1 General

.1 Conform to the requirements of ACI and the following to protect freshly deposited concrete from abnormally high temperatures or temperature differentials, premature drying, and moisture loss for a period of time necessary to develop the specified properties of the concrete

.2 Hot Weather Concreting:

.1 When rate of moisture evaporation exceeds 1.0 kg/rn2 per hour, employ the following measures in addition to the requirements of ACI.

.1 Use ice as mixing water to lower the concrete temperature.

.2 Dispatch ready-mix trucks and organize work to keep mixing time to a minimum. Minimize exposure of mixing trucks to the hot sun while waiting.

.3 Provide adequate personnel and organize work to keep placing time to a minimum.

.4 Place concrete in layers thin enough and areas small enough so that the time interval for placing is reduced and compACIion will ensure complete union of adjacent portions.

.5 With formed concrete, reliance shall not be placed on the forms alone to provide curing. Spray formwork with water to keep it tight and free from cracking.

.3 Protection of Completed Work

.1 At all times during the work, protect exposed concrete from staining or becoming coated with concrete leakage due to continuing concreting operations. Members which become coated may be classed as defective by the Consultant.

.2 Protect exposed members from staining due to rusting of reinforcement or ties projecting beyond construction joints.

8.3.4 FOUNDATION MAT

.1 Found foundation mat on the blinding slab and the waterproofing which have been placed on naturally consolidated undisturbed soil capable of safely developing the allowable bearing capacity shown on the drawings within acceptable limits of settlement.

.2 Founding elevations shown are based upon the geotechnical investigation.

.3 Founding elevations and allowable bearing capacities must be verified by the geotechnical Consultant before mat concrete is placed.

.4 If, upon excavating to the elevations shown, the required soil bearing capacities are not achieved, inform the Consultant who will provide written instructions as to how to proceed.

.5 Note actual footing founding elevations on the reproducible as-built drawings

Remove water, disturbed soil and foreign matter from footing excavations before placing blinding concrete. Do not permit the soil at founding elevations to soften due to the presence of water in the excavations or construction activity.

.6 Remove water, disturbed soil and foreign matter from footing excavations before placing blinding concrete. Do not permit the soil at founding elevations to soften due to the presence of water in the excavation or construction activity.

.7 Remove water, and foreign matter from excavations before placing concrete.

8.3.5 CONSTRUCTION JOINTS

.1 Obtain approval from the Consultant for location and details of construction joints riot shown.

.2 The maximum length of a concrete pour shall be 40 m.

.3 The maximum height of a concrete pour shall be 5 m.

3.3.6 WATERSTOPS

1 Maintain waterstops in position during placing of concrete. Support the waterstops during the progress of the work to ensure the proper embedment in the concrete. Equally divide the symmetrical halves of the waterstops between the concrete pours at the joints. The centre axis of the waterstops shall coincide with the joint openings at the plane of installation of the waterstop. Ensure maximum density and imperviousness of the concrete by thoroughly working it in the vicinity of all joints.

2 Place concrete around waterstops by careful working, routing, and

vibrating to ensure that all air pockets have been eliminated.

8.3.7 SEPARATION STRIPS

1 Place concrete in the separation strips after concrete in adjacent areas has cured for the duration noted on the drawings. and until the mean daily ambient temperature is approximately 18 degrees C.

8.3.8 TREATMENT OF FORMED SURFACES

.1 Do work in accordance with ACI 318 and as follows:

.2 Provide smooth form finish to concrete surfaces exposed to public view and surfaces to receive plaster, damp-proofing, moisture resistant membrane and the like.

.1 Remove traces of form lining compound from concrete surfaces which may affect the bonding of following surface application.

8.3.9 OPENINGS THROUGH COMPLETED MEMBERS

.1 Do not cut openings through completed members without the Consultant’s written approval.

.2 Where the location of openings is approved, locate the reinforcement by x-ray, cover meter or other positive means as required by the Consultant and adjust the location of the opening so that no reinforcement is cut unless specifically approved otherwise in writing by the Consultant.

8.3.10 MAKING GOOD

.1 Where directed by the Consultant Make good temporary openings left in concrete construction around pipes, ducts and the like using a mortar of the same proportions as the surrounding work. Reinforce mortar with welded wire fabric where openings exceed 75 mm . Roughen existing surfaces to receive mortar or apply suitable bonding agent such that mortar will be securely bonded to existing concrete.

8.3.11 GROUTING BENEATH BASE PLATES

.1 Grout beneath plates bearing on concrete with an approved non-shrink flowable grout. Conform with the manufacturer’s directions for mixing and placing grout. Completely fill voids below plates. Fill voids left by shims after shims are removed.

.2 Refer to Section 05120 for lifting of baseplates to determine adequacy of grouting. If defects are found, more base plates will be raised.

.3 Well in advance of grouting the actual column base plates, provide a minimum of two consecutive successful grouting mock-ups. The mock-ups shall be executed using base plates of 1700 x 1700 x at least 150 mm thick, using the same base plate leveling system as in the building base plates. The thickness of grout shall be the same as for the building base plates. The base plate mock-ups shall be executed in a concrete depression of size and side clearances equal to those of the actual conditions in the building base plates. The crew executing the mock-up, including supervisor and workers, shall be the same crew as will carry out the actual building base plate grouting. A grouting operation will be judged successful. if the grout achieves at least the specified strength and if the area of voids at the contact surface between the grout and the underside of the base plate is less than 30% of the surface of the base plate.

8.3.12 FOUNDATION MAT

.1 Massive pours may set up temperature rises and gradients that may cause severe cracking and in extreme cases, loss of strength.

.2 Plan and carry out concreting operations, protect and cure the concrete so as to prevent these conditions from occurring.

.3 Design mix and employ construction procedures in accordance with ACI such that the maximum temperature in the concrete and the maximum temperature difference from interior of mass to outside face do not exceed those specified in ACI. Use insulation or other approved techniques to achieve this.

.4 Conduct an off-site mat concrete test pour, minimum size is 5 m x 5 m x mat thickness, using the proposed mix design and a representative volume of concrete. The Owners inspection and testing company will install arid monitor thermocouples in both the test pour and all the final pours and

report the temperature results achieved. In addition to the other requirements of this arid other related specification sections, adhere to the following:

.1 Maximum size of aggregate: 40 mm.

.2 Temperature of the concrete at the time of placing: between 70C and 210C

.6 Provide appropriate insulation arid protection to the concrete surfaces for at least 7 consecutive days immediately after concrete placement.

.7 Do not remove insulation and protection until the temperature between average ambient and 75 mm below the top of concrete is 300C or less. Use a system of thermocouples placed at or below the surface of the concrete to determine concrete temperature.

.8 Plan the entire concreting operation in advance taking into account rate of pour, size and number of high frequency vibrators, nature, capacity and location of housing equipment, possible use of a retarder, ability to receive, place and discharge at the planned rate and the like. Submit the plan , sequencing and schedule of operation to the Consultant in advance, along with the concrete mix.

.9 Place concrete in maximum 450 mm lifts and thoroughly vibrate each layer and extend vibration into lower layers.

.10 Advance each layer at least 6 metres before starting next layer.

.11 Employ necessary procedures to keep temperature differential within concrete to 200C or less.

8.3.13 WATER STORAGE TANKS (WATER TIGHT CONSTRUCTION)

.1 Conform with the requirements of this section and the following for the construction of the walls and base slabs of the water storage tanks members designated to be watertight.

.2 Temperature Control

.1 Concrete temperature at time of delivery 270C . maximum, 180C minimum.

.2 Maximum cooling rate not to exceed 70C. per day.

.3 In the case of the base slab, employ a temperature monitoring system during each pour to determine the internal concrete temperature at regular intervals. Submit details of the proposed monitoring system to the Consultant for review.

.3 Curing

.1 Maintain 7 days continuous moist curing after placing concrete. Provide an approved membrane waterproofing immediately thereafter.

.4 Crack Repair

.1 Just prior to the installation of the tank liner arid insulation, carefully examine all exposed interior and exterior surfaces and repair any cracks in them.

.5 Water Test

.1 At least 28 days after concreting the last section of each tank, and after the sealing of joints, fill each tank with water and leave standing for 10 days.

.2 Fill each tank gradually such that the differential temperature between the water and the tank concrete does not exceed 70C.

.3 Locate and repair all areas where leakage occurs and retest until each tank is watertight.

8.3.14 QUALITY CONTROL

.1 Implement a system of quality control, as per ACI 301 and ACI 311.1 R, ACI 311 .4R, ACI 311 .5R to ensure that the minimum standards specified herein are attained.

.2 Bring to the attention of the Consultant any defects in the work or departures from the Contract Documents which may occur during

Construction. The Consultant will decide upon corrective action and give his recommendations in writing to the Project Manager.

.3 The Consultants general review during construction and inspection and testing by independent inspection and testing agencies reporting to the Consultant are both undertaken to inform the Project Manager of the Contractors performance and shall in no way augment the Contractors quality control or relieve the Contractor of contractual responsibility.

8.3.15 NOTI FICATION

.1 Prior to commencing significant segments of the work, give the Consultant and independent inspection and testing agencies. appropriate notification so as to afford them reasonable opportunity to review the work. Failure to meet this requirement may be cause for the Consultant to classify the work as defective.

8.3.16 INSPECTION AND TESTING

.1 Appointment of Independent Inspection and Testing Companies.1 The Project Manager will appoint the Independent Inspection and

Testing Companies to make inspections or perform tests as the Consultant requests. The Independent Inspection and Testing Companies shall be responsible only to the Consultant, and shall make only such inspections or tests as the Consultant may direct.

.2 When defects are revealed, the Owner may request, at the Contractors expense, additional inspection or testing to ascertain the full extent of the defect.

.2 Tests on Concrete Materials

.1 Cement and Aggregates: The Consultant may make tests on these materials as deemed necessary during the work.

.2 Concrete Strength: Specimen testing will be carried out in accordance with ACI 318 , ACI 311.1R, ACI 311.4R, and ACI 311.5R, and as follows: Six companion laboratory cured concrete standard compression test specimens; three tested at 28 days and three tested at 7 days, constitute a strength test. The results of the 7 day tests related to curing procedure shall be the basis to strip soffit forms from horizontal or inclined members. For concrete with strength specified at 56 days, nine companion specimens shall be required. Three are to

be tested at 7 days, three at 28 days, and three at 56 days.

.3 Heavyweight Concrete: In addition to the above tests, fresh weight and dry weight tests may be made on a sampling basis.

.4 Grout Under Baseplates: At least one strength test may be made each day that grout is placed under baseplates.

.3 Inspection of Soil

.1 Soil at founding elevations will be inspected.

8.3.17 DEFECTIVE MATERIALS AND WORK

.1 Where evidence exists that defective work has occurred or that work has been earned out incorporating defective materials, the Consultant may have tests, concrete coring, inspections or surveys performed, analytical calculations of structural strength made and the like in order to help determine whether the work must be repaired or replaced.

.2 All testing shall be conducted in accordance with the requirements of the Egyptian Code, the UBC, ACI and ASTM Standards except where this would in the Consultant’s opinion cause undue delay or give results not representative of the rejected material in place. The most stringent requirement shall be used. in this case, the tests shall be conducted in accordance with the standards given by the Consultant.

.3 Materials or works which fail to meet specified requirements may be rejected by the Consultant whenever found at any time prior to final acceptance of the work regardless of previous inspection. If rejected, defective materials or work shall be promptly removed and replaced or repaired to the satisfaction of the Consultant, at no expense to the Owner.

BILL NO.

Sec. No.

Code Item No.

DescriptionQty. Unit Rate

/L.E

8,9

01

CAST – IN – PLACE CONCRETE

Provide all labor, materials (including rebars for R.C), hoisting, plumping, vibration and finishing equipment to cast structural concrete including all design devices required. Concrete unit rate shall include the preparation of drawings and coordination of embeds, shift work, supervision thereof special handling associated with hot weather casting restrictions, curing and any other provisions of finishes.

ORDINARY CONCRETESupply and apply O.C for foundations and pile cap Consisting of : 0.8 m³ coarse aggregate, 0.4 m³ fine aggregate and 250 Kg cement.

m³

02 Supply and apply O.C below foundation for retaining walls and of consisting of: 0.8 m³ coarse aggregate, 0.4 m³ fine aggregate and 250 Kg cement.

m³

01

STRUCTURAL REINFORCED CONCRETE

BEAM 250 - 300 Kg/cm²02030405

Columns 350 / 400 / 550 / 600 Kg./m²Core and Shear WallsSlabsStair Landing, and risers.

m³m³m³m³