NIOEC-SP-10-01(0) DOCUMENT CODE NO. OF SHEETS: 26 PLAN/PRJ/SUB UNIT PHASE DISCIPLANE DOCUMENT. TYPE SERIAL NO. REV. NO. DATE NIOEC 000 EG CE SP 1001 A0 JULY 2005 NATIONAL IRANIAN OIL REFINING & DISTRIBUTION COMPANY NATIONAL IRANIAN OIL ENGINEERING & CONSTRUCTION COMPANY NIOEC SPECIFICATION FOR CONCRETE FIRST EDITION JULY, 2005 THIS SPECIFICATION IS THE PROPERTY OF NATIONAL IRANIAN OIL ENGINEERING & CONSTRUCTION COMPANY. IT IS CONFIDENTIAL AND ALL RIGHTS RESERVED TO THE OWNER. NEITHER WHOLE NOR ANY PART OF THIS DOCUMENT MAY BE DISCLOSED TO ANY THIRD PARTY, REPRODUCTED, STORED IN ANY RETRIEVAL SYSTEM OR TRANSMITTED IN ANY FORM OR BY ANY MEANS WITHOUT THE PRIOR WRITTEN CONSENT OF THE NATIONAL IRANIAN OIL ENGINEERING & CONSTRUCTION COMPANY.
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NIOEC-SP-10-01(0) DOCUMENT CODE NO. OF SHEETS: 26
PLAN/PRJ/SUB UNIT PHASE DISCIPLANE DOCUMENT. TYPE SERIAL NO. REV. NO. DATE NIOEC 000 EG CE SP 1001 A0 JULY 2005
NATIONAL IRANIAN OIL REFINING & DISTRIBUTION COMPANY
NATIONAL IRANIAN OIL ENGINEERING
& CONSTRUCTION COMPANY
NIOEC SPECIFICATION
FOR
CONCRETE
FIRST EDITION
JULY, 2005
THIS SPECIFICATION IS THE PROPERTY OF NATIONAL IRANIAN OIL ENGINEERING & CONSTRUCTION COMPANY. IT IS CONFIDENTIAL AND ALL RIGHTS RESERVED TO THE OWNER. NEITHER WHOLE NOR ANY PART OF THIS DOCUMENT MAY BE DISCLOSED TO ANY THIRD PARTY, REPRODUCTED, STORED IN ANY RETRIEVAL SYSTEM OR TRANSMITTED IN ANY FORM OR BY ANY MEANS WITHOUT THE PRIOR WRITTEN CONSENT OF THE NATIONAL IRANIAN OIL ENGINEERING & CONSTRUCTION COMPANY.
JULY, 2005 NIOEC-SP-10-01 ( 0 )
JULY, 2005 NIOEC-SP-10-01 ( 0 )
REVISION INDEX
REV. PAGE
1 2 3 4 5 REV. PAGE
1 2 3 4 5 REV. PAGE
1 2 3 4 5 REV. PAGE
1 2 3 4 5
1 26 51 76
2 27 52 77
3 28 53 78
4 29 54 79
5 30 55 80
6 31 56 81
7 32 57 82
8 33 58 83
9 34 59 84
10 35 60 85
11 36 61 86
12 37 62 87
13 38 63 88
14 39 64 89
15 40 65 90
16 41 66 91
17 42 67 92
18 43 68 93
19 44 69 94
20 45 70 95
21 46 71 96
22 47 72 97
23 48 73 98
24 49 74 99
25 50 75 100 NOTES:
1) THIS SHEET IS A RECORD OF ALL REVISIONS TO THIS SPECIFICATION. 2) REMARKS RELATED TO EACH REVISION SHOW A BRIEF DESCRIPTION. THESE REMARKS SHALL BE
INTERPRETED IN CONJUNCTION WITH THE REVISED TEXT MARKED BY REVISION NUMBERS. 3) WHEN APPROVED EACH REVISION SHALL BE CONSIDERED AS A PART OF THE ORIGINAL DOCUMENT. 4) NUMBER OF PAGES EXCLUDES THIS SHEET AND THE COVER SHEET.
NIOEC Specifications cover the general requirements for detailed engineering procurements, testing inspection & construction of refinery/oil plant, distribution depots, pump stations and pipe lines. This NIOEC Specification covers minimum requirements for Design and Construction of reinforced Concrete structures.
2. REFERENCES
Throughout this Specification the following dated and undated standards/codes are referred to these referenced documents shall, to the extent specified here in, form a part of this Specification. For undated references, the latest edition of the referenced document (including any supplements and amendments) applies. For dated references, the edition cited applies. The applicability of changes in dated references that occur after the cited date, shall mutually be agreed upon by NIOEC and the Vender / Contractor.
UBC ( UNIFORM BUILDING CODES )
" UBC 1997 Edition " ACI ( AMERICAN CONCRETE INSTITUTE ) ACI-211 " Proportioning Concrete Mixes "
ACI-305 " Hot weather Concreting "
ACI-306 " Cold Weather Concreting "
ACI-315 " Manual of Standard Practice for detailing Reinforced Concrete Structures. "
ACI-318 " Building Code Requirements for Reinforced Concrete. " ACI-347 " Recommended Practice for Concrete from work. " ACI-304 "Recommended Practice for Measuring Mixing and Placing Concrete" ACI-350 R " Concrete Sanitary Engineering Structures "
ASTM ( AMERICAN SOCIETY FOR TESTING AND MATERIALS )
ASTM C150 " Standard Specification for Portland Cement "
ASTM C109-86 " Method of Test for compressive Strength of Hydrulic Cement
Mortars "
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ASTM C 33-86 " Specification for Concrete Aggregates"
ASTM A 615 " Plain reinforcing steel "
ASTM A 496 " Standard Specification Welded Steel wire fabric for concrete.
reinforcement."
ASTM A 497 " Standard Specification for weld deformed Steel wire fabric for
concrete reinforcement."
ASTM C 94-866 "Specification for Ready-mixed Concrete "
ASTM C 260-86 "Specification for Air-Entraining Admixtures for Concrete "
ASTM C 496-86 "Specification for Chemical Admixtures for Concrete "
ASTM C 989-87a "Specification for Ground Iron Blast Furnace in Cement "
ASTM C 618-87 "Specification for Fly Ash and Raw or calcined Natural pozzolan for
mineral Admixture in Portland Cement Concrete. "
ASTM C171-87 "Test Method for Compressive strength of Natural Building "
ASTM C172-82 "Method of Sampling freshly Mixed Concrete "
ASTM C309-81 " Specification for Liquid Membrane-Forming compounds for curing
Concrete "
ASTM C 144-87 "Specification for Aggregate for Masonry Concrete."
ASTM C 31-88 " Test Method of Making and curing Concrete test Specimens in the
Field."
ASTM C 143-78 " Test Method for Slump of Portland cement Concrete."
AASHTO ( AMERICAN ASSOCIATION OF STATE HIGHWAYS AND
TRANSPORTATION ORGANIZATION )
AASHTO T260-84 " Method of sampling and Testing for total chloride Ion in
Concrete and Concrete Raw Materials.
NIOEC-SP ( NIOEC SPECIFICATIONS )
NIOEC-SP-00-10 " NIOEC Specification for Units "
Where reference is made to "Building Official", this designation for the purpose of this contract shall mean the Employer. Copies of the ACI Building code and all other applicable standard specifications, last edition (specifically the following American society for testing and materials). For general list of standards used in this Specification refer to section 3-8 of ACI code 318 M-89 plus the Portland cement Association "Design and control of concrete Mixtures "Which shall be supplied by the contractor and shall be available at the job site for reference as required.
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3. UNITS International system of unites (SI) shall be used in accordance with NIOEC-SP-00-10, unless otherwise specified.
4. GENERAL
4.1 Contractor shall design all the concrete structures. Design shall include computations and the preparation of the engineering drawings to show the general arrangement of the members, and all other information in the form of notes and diagrams necessary for the proper interpretation of the designer's ideas. All the design work should be in accordance with the codes mentioned in Articles 2. and 14. of this Specification.
The Contractor shall furnish all materials (except as noted in the Contract.), loots, equipment, utilities (except as noted), facilities scaffolding, etc., and shall perform all labor and services necessary for the proper execution and completion of all concrete work as shown on the drawings, as specified herein and/or reasonably implied there by to carry out the apparent intent of the work.
4.2 The Contractor's scope of work shall include the following item:
- Design of all the concrete structures and preparation of all the engineering drawings.
- Design, construction and removal of forms including scaffolding and required supports.
- The furnishing, cutting, bending and placing of reinforcing steel and reinforcing
accessories.
- Concrete including admixtures, mixing, placing finishing, protection and curing.
- The placing of moisture barriers, anchor bolts, sleeves. Inserts, trench angles and other embedded items detailed on the concrete drawings. Embedded items not detailed on concrete drawings such as electrical conduit, boxes, etc. Will be placed under other parts of this specification.
- Expansion and contraction joints, water stops, keyways and similar items as shown on
the drawings and/ or herein specified.
- Providing suitable openings through the concrete as necessary for the proper installation, attachment and/or passing of the work of other trades.
- Preparation of concrete surfaces for grouting and dry packing.
- Surface preparation of concrete for protective coatings and hardeners. The Contractor will
furnish hardeners.
- One site bench mark will be furnished by Employer. Contractor shall establish the necessary lines and elevations for his own work. The contractor for verification and use by Employer shall carefully preserve all stakes and marks.
Item excluded from this part of specification is: - Masonry work.
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5. MATERIALS
5.1 Cements Cement shall be an approved band of Portland cement conforming to "standard specification for Portland cement ASTM C 150 Type I through Type V at the employer's option, according to soil report service of the structure. Cement shall be mill tested and duplicate copies of mill test reports covering cement to be used in the work shall be furnished to the Employer. One brand of cement shall be used throughout the work to maintain uniform color and to establish undivided responsibility on sibilate. Other types of cement can be used for specific jobs, provided the contractor obtains written approval of Employer whenever and when a change of cement is needed.
5.2 Admixtures
Admixtures to increase workability, hardness or other desirable characteristics may be only used if prior written approval by the Employer has been obtained.
5.3 Water Water used in mixing concrete shall be clean and free from injurious amounts of oils, acids alkalis, salts, organic materials, or other substances that may be deleterious to concrete or steel. Mortar cubes made with non potable mixing water such as sea water shall have 7-day and 28-day strengths equal to at least 90 percent of the strength of similar specimens made with potables water, when tested in accordance with "Method of Test for Compressive Strength of Hydraulic Cement Mortars" (ASTM C 109-86.).
5.4 Aggregates Aggregates shall conform to the requirements of "Specifications for Concrete Aggregates" ASTM C33-86. Fine and coarse aggregates shall be regarded as separate ingredients. Each size of coarse aggregate, as well as the combination of sizes when two or more are used, shall conform to the grading requirements of the appropriate ASTM specifications.
6. PROPORTIONING
6.1 Strength
All concrete shall meet the requirements of quality specified in Chapter 5.3 of the ACI 318 code and shall meet the following minimum cylinder compressive strength requirements:
- For water basins: fc ' ≥ 28.1 N/mm2 (4000 Psi) - For precast concrete
Pipe rack: fc ' ≥ 25.0 N/mm2 (3500 Psi) - For structures, foundations,
Paving and for all other Structural concrete works: fc ' ≥ 21.0 N/mm2 (3000 Psi)
- For fireproofing and duct Banks: fc ' ≥ 18.0 N/mm2 (2500 Psi)
- For lean concrete: fc ' ≥ 8.0 N/mm2 (1100 Psi) 6.2 Slump
The concrete consistency as determined by the slump concrete test (ASTM C143-89a) shall have the following range:
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Recommended Slumps for Various Types of Construction
SLUMP, mm CONCRETE
CONSTRUCTION MAXIMUM * MINIMUM
Reinforced foundation walls and footings
Plain footings, caissons, and substructure walls
Beams and reinforced walls
Building columns
Pavements and slabs
Mass concrete
75
75
100
100
75
75
25
25
25
25
25
25
* May be increased 25 mm for consolidation by hand methods such as rodding and spading
The minimum slump shall be waived on concrete used in ramps or other sloping construction.
6.3 Maximum Size of Coarse Aggregate The nominal maximum size of the aggregate shall not be larger than one-fifth of the narrowest dimension between sides of forms, one-third of the depth of slabs, nor three-fourths of the minimum clear distance between reinforcing bars or between bars and forms whichever is least. In columns the nominal maximum size of the aggregate shall be limited as above but shall not be larger than two-thirds of the minimum clear distance between bars or between tie bars and forms.
6.4 Proportioning of ingredients
The proportioning of concrete ingredients shall conform to chapter 5.3 of the ACI 318-02 code.
7. FORMWORK
- The design and engineering of the formwork as sell as its construction, shall be the
responsibility of the Contractor, but will be subject to the approval by the Employer. The Contractor for approval by the Employer before starting the construction shall submit typical drawings showing the proposed formwork. Concrete forms shall be square, plumb and adequately braced to prevent shifting during the placing of concrete.
- Selection of the materials for formworks should be consistent with safety and the quality
required in the finished work. The Employer could use lumber, plywood, steel, aluminum, and other materials in formworks subject to the approval. For exposed concrete above grade, smooth faced material such as metal or plywood shall be used.
For more detail refer to chapter 4 of ACI 347-78. - Temporary openings shall be provided at the base of column forms and wall forms and
at other points when necessary to facilitate cleaning and observation immediately before concrete is deposited.
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- The external corners of columns, beams, walls, and foundations above grade shall be formed with 25 mm chamfer.
- Forms shall be sufficiently tight to prevent leakage of grout or cement paste. The use of
wire ties to hold the forms together shall not be permitted. - Plywood and other wood surfaces shall be scaled against absorption of moisture from the
concrete by a commercial form-oil or sealer. - Form release agents shall be applied to the form contact surfaces to prevent bond and
thus facilitate stripping. - When forms are coated to prevent bond with concrete, the coating shall not be allowed
to stand in puddles in the forms nor allowed to come in contact with concrete against which fresh concrete will be placed.
- Batter boards with sufficient structural strength shall be installed at top of slabs or
foundation mats to firmly locate the piers before any concrete is cast for the slab or mat. - All form surfaces shall be cleaned and repaired before reuse. - Vertical forms shall be made in such a manner that they can be loosened or stripped to
allow watering on vertical concrete surfaces for curing. - Removal of Forms Period before formwork shall be removed (days) ACI-318-M-89
Ordinary P. Cement
Concrete Rapid-hardening P. Cement
Concrete Formwork k Cold Weather
(just above freezing)
Normal Weather
(10 ْ– 27 ْC)
Cold Weather (just above freezing)
Normal Weather (10 ْ– 27 ْC)
Beam Sides, Walls Columns,
6 2 5 1
Slabs (props Left under)
10 3 7 2
Beam soffits (left under)
14 7 10 4
Removal of props to slabs
21 7 14 4
Removal of props to beams
28 16 21 8
Whenever the formwork is removed during the curing period the exposed concrete shall be cured by one of the methods of curing as described hereinafter. Damaged surfaces shall be repaired within 24 hours of from removal, but not before Employer's knowledge and approval.
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8. REINFORCEMENT
- Details of concrete reinforcement not covered herein shall be in accordance with "Building Code Requirements for Reinforced Concrete" (ACI 318-83-89) and "Manual of Standard Practice for Detailing Reinforced Concrete Structures" (ACI 315-80-86).
in accordance with ASTM A 615 or alternative equivalent material upon NIOEC approval.
- Welded wire fabric shall be Grade 70 (minimum yield strength 485 N/mm2) in
accordance with ASTM standard A 496 and A 497 or alternative equivalent material upon NIOEC approval.
- Local manufactured reinforcing steel bars and welded Wire Fabric with different
properties than specifics in item 6.2, 6.3 and 6.4 above may be used with Employer's approval provided the design is also adjusted accordingly.
8.1 Fabricating and Placing Tolerances
- Bars used for concrete reinforcement shall meet the following requirements for
fabricating tolerances:
a. Sheared length : ± 25 mm. b. Depth of truss bars : ± 12 mm. c. Length of truss bars: 22 mm bar or smaller ±0, -12 mm 25 mm bar or larger ±0, -25 mm
d. Stirrups, ties and spirals: ± 12 mm. e. All other bends: ±25 mm.
- Bars shall be placed to the following tolerances:
a. Concrete cover to formed surfaces: ±6 mm b. Minimum spacing between bars: -6 mm. c. Top bars in slabs and beams:
a. Members 200 mm deep or less: ±6 mm. b. Members more than 200 mm but not over 600 mm deep: ±12 mm.
d. Crosswise of members: spaced evenly within 25mm.
e. Lengthwise of members: ±25 mm. f. Members more than 600 mm deep: ±25 mm.
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- Bars may be moved as necessary to avoid interference with other reinforcing steel, conduits, or embedded items. If bars are moved more than one bar diameter or enough to exceed the above tolerances, the resulting arrangement of bars shall be subject to approval by the Employer, Extra bars may have to be added to maintain the design requirements.
- All reinforcing bars shall be supported and wired together to prevent displacement by
construction loads or the placing of concrete beyond the tolerances specified in Paragraph 6.5. Where the concrete surface will be exposed to the weather in the finished structure, the portions of all accessories in contact with the formwork shall be galvanized or shall be made of hard plastic.
- Unless permitted, reinforcement shall not be bent after being partially embedded in
hardened concrete.
- Development and splices of reinforcement shall be in accordance with ACI 318 chapter 12 Development And Splices of Reinforcement and chapter 21 provision for seismic design.
9. JOINTS AND EMBEDDED ITEMS
9.1 Construction Joints
- Joints not shown on the drawings shall be so made and located as to least impair the strength of the structure and shall be approved. In general, they shall be located near the middle of the spans of slabs, beams and girders unless abeam intersects a girder at this point, in which case the joints in the girders shall be offset a distance equal to twice the width of the beam. Provision shall be made for transfer of shear and other forces through the construction joint. Joints in walls and columns shall be at the underside of floors, slabs, beams or girders, brackets, column capitals, haunches and drop panels shall be placed at the same time as slabs, joints shall be perpendicular to the main reinforcement.
- All reinforcing steel and mesh shall be continuous across joints.
- The surface of the concrete at all joints shall be thoroughly cleaned and all laitance
removed.
- Vertical joints shall be thoroughly wetted, and slushad with a coat of neat cement grout immediately before placing of new concrete.
- When required or permitted, bond shall be obtained by one of the following methods:
a. The use of an approved adhesive. b. The use of an approved chemical retarder which delays but does not prevent
setting of the surface mortar. Retarded mortar shall be removed within 24 hours after placing to produce a rough exposed aggregate bonding surface.
c. By roughening the surface of the concrete in an approved manner which will
expose the aggregate uniformly and will not leave laitance, loosened particles of aggregate or damaged concrete at the surface.
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9.2 Expansion Joints Expansion joints and water stops shall be provided as necessary and shall be made as shown on the construction drawings but in no case shall be more than. 60 ft. apart. For concrete slab this dimension shall not be more than 20 ft. These limits may be increased provided that thermal loads have been properly taken into account in the structural design. A hydro-carbon resistant compound should seal the joint as per manufacturer's direction.
9.3 Other Embedded Items
- Anchor bolts with diameter less than 38.1mm(1 1/2") may not be placed in sleeves. All anchors bolt 1 1/2" and over must be placed in sleeves. All sleeves, inserts, anchors, and embedded item required for adjoining work or for its support shall be placed and securely located prior to concreting. All anchor bolts shall be set with substantial templates locating the bolts with a tolerance in relation to the plant coordinate system of ±2 mm for bolts up to 25.4 mm (1 inch) diameter and ±4 mm for anchor bolts larger than 25.4 mm (1 inch) diameter. The axial alignment tolerance for anchor bolts shall not exceed ±1 mm in the radial direction to 10 mm in the axial direction of the bolt.
- Anchor bolts shall have a minimum clearance of 63.5mm (2 1/2") bolt diameters from
the center line of bolts to edge of concrete, but not less than 10 cm. (4 inch). Minimum distance between edge of sleeves and concrete shall be 7.5 cm. (3 inch).
- Contractor shall furnished and place embedded items before the concrete in places.
- Anchor bolts shall not be heated to facilitate equipment installation.
9.4 Placing Embedded Items
Expansion joint material, water stops, and embedded item shall be positioned accurately and supported against displacement. Voids in sleeves, inserts, and anchor slots shall be filled temporarily with readily removable material to prevent the entry of concrete into the voids. The Employer shall be given at least 24 hours check-out time after placement of embedded items and before depositing concrete.
9.5 Sliding Supports
Sliding supports shall be provided at one end of equipment subject to thermal expansion such as heat exchangers. The sliding shall be by means of slotted holes on saddles. Suitable precut friction pads shall be provided for such foundations and double nuts fitted to the foundation bolt at the sliding end.
10. MIXING
10.1 Measuring Amounts of Materials for Mixing
- Cement and aggregates shall be measured by weight with a tolerance of 1% for cement
and 2% for aggregates.
- Water shall be measured by either a calibrated thank, metered or weighed, automatic meters, or other methods approved by the Employer, Any method used should be capable of routin measurement within an accuracy of one percent under all operating conditions.
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10.2 Ready – Mixed Concrete
Ready – mixed concrete shall be mixed and transported in accordance with "Specifications for Ready-mixed Concrete" (ASTM C94-86b).
10.3 Batch Mixing at Site
- The concrete shall be mixed in a batch mixer conforming to the approval of the
Employer. The mixer shall bear the manufacturer's rating plate indicating the rated capacity and the recommended revolutions per minute, and shall be operated in accordance with these recommendations. It shall be equipped with a suitable charging hopper, water storage tank, and a water-measuring device, and shall be capable of thoroughly mixing the aggregates, cement, and water into a uniform mass within the specified mixing time, and of discharging the mix without segregation.
- Any liquid admixture shall be dispensed by means of an automatic dispenser or similar
metering device. Powdered a admixtures shall be weighed or measured by volume as recommended by the manufacturer. The accuracy of measurement of any a admixture shall be within ±1 per cent.
- The batch shall be so charged into the mixer that some water will enter in advance of the
cement and aggregates. Water shall continue to flow for a period which may extend to the end of the first 25 percent of the specified mixing time. Controls shall be provided to insure that the batch cannot be discharged until the required mixing time has clasped. Controls shall be provided to insure that no additional water may be added during mixing. The entire batch shall be discharged before the mixer is recharged.
- Each batch of 1 m3 or less shall be mixed for not less than 2 minutes. The mixing time
shall be increased 20 seconds for each additional cubic meter or fraction thereof.
- The mixing period should be measured from the time when all the solid materials are in the mixer. The mixer shall be clean, and the pick-up and throw-over blades in the drum shall be replaced when they have lost 10 per cent of their original depth.
10.4 Retempering
- Concrete shall be mixed only in quantities for immediate use. Concrete which has set
shall not be retempering, but shall be discarded.
- Indiscriminate addition of water to increase slump shall be strictly prohibited.
- When concrete arrives at the project with slump below that suitable for placing, water may be added only if neither the maximum permissible water-cement ratio nor the maximum slump is exceeded. The water must be incorporated by additional mixing equal to at least half of the total mixing required. Any addition of water above that permitted by the limitation on water cement ratio must be accompanied by a quantity of cement sufficient to maintain the proper water-cement ratio. Such addition must be approved by the Employer.
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10.5 Hot Weather Concreting
Whenever placing or curing concrete in hot weather, recommendation as outlined in "Recommended Practice for Hot Weather concreting" (ACI 305-72) shall apply.
10.6 Cold Weather Concreting
Whenever placing or curing concrete in cold weather, recommendations as outlined in "Recommended Practice for cold Weather Concreting"(ACI-306-78) shall apply.
11. DURABILITY REQUIREMENTS
11.1 Freezing and Thawing Exposures
- Normal density and low-density concrete exposed to freezing and thawing or deicer chemicals shall be air entrained with air content indicated in Table 3. Tolerance on air content as delivered shall be ±1.5 percent. For specified compressive strength fc greater than 35 MPa, air content indicated in Table 3 may be reduced 1 percent.
TABLE 3- TOTAL AIR CONTENT FOR FROST – RESISTANT CONCRETE
1) See ASTM C 33 for tolerances on oversize for various nominal maximum size
designations. 2) These air contents apply to total mix, as for the preceding aggregate sizes. When
testing these concretes, however, aggregate larger than 37.5 mm is removed by hand-picking or sieving and air content is determined on the minus 37.5 mm fraction of mix, (Tolerance on air content as delivered applies to this value) Air content of total mix is computed from value determined on the minus 37.5 mm fraction.
- Concrete that will be subject to freezing and thawing in a moist condition, intended to have low permeability to water or be exposed to deicing salts, brackish water, sea water, or spray from these sources shall conform to the requirements of Table 4.
11.2 Requirement for Special Exposure Conditions
- When reinforced concrete will be exposed to deicing salts, brackish water, sea water or
spray from these sources, requirements of Table 4 for water-cement ratio or concrete strength and minimum concrete cover requirements of Clause 13.7 shall be satisfied.
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TABLE 4 – REQUIREMENTS FOR SPECIAL EXPOSURE CONDITIONS
EXPOSURE CONDITION
MAXIMUM WATER-CEMENT RATIO,
NORMAL DENSITY AGGREGATE CONCRETE
MINIMUM F' LOW-DENSITY
AGGREGATE CONCRETE
Concrete intended to have low Permeability when exposed to water
0.50 25
Concrete exposed to freezing and thawing in moist condition 0.45 30
For corrosion protection for reinforced Concrete exposed to deicing salts, brackish Water, seawater or spray from these sources
0.40* 30*
Watertight concrete In fresh water In seawater
0.50 0.45
25 30
Frost-resistant concrete Thin sections; any section with less than 50 mm" cover over reinforcement and any concrete exposed to deicing salts All other structures
0.45
0.50
30
25
Exposure to sulfats moderate sever
0.5 0.45
25 30
Placing concrete under water Not less than 386 kg of cement per cubic meter
Floors on grade Select water-cement ratio for strength, plus minimum cement Requirements, Table 8
Note: If minimum concrete cover required by Clause 13.7 is increased by 10 mm, water-cement
ratio may be increased to 0.45 for normal density concrete, or fc ' reduced to 30 Mpa for low-density concrete.
- For corrosion protection, maximum water soluble chloride ion concentrations in
hardened concrete at ages from 28 to 42 days contributed from the ingredients including water, aggregates, cementations materials and admixtures shall not exceed the limits of Table 5 When testing is performed to determine water soluble chloride ion content, test procedures shall conform to AASHTO T 260-84.
TABLE 5 – MAXIMUM CHLORIDE ION CONTENT FOR CORROSION PROTECTION
TYPE OF MEMBER MAXIMUM WATER SOLUBLE CHLORIDE ION (Cr) IN CONCRETE, PERCENT BY MASS
OF CEMENT Prestrssed concrete Reinforced concrete exposed to chloride in service Reinforced concrete that will be dry or protected from moisture in service Other reinforced concrete construction
0.06 0.15
1.00
0.30
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- Concrete to be exposed to sulfate-containing solutions or soils shall conform to requirements of Table 6, or be made with cement that provides sulfate resistance and used in concrete with maximum water-cement ratio or minimum compressive strength from Table 6.
- Calcium chloride as an admixture shall not be used in concrete to be exposed to severe or
very severe sulfate-containing solutions, as defined in Table 6.
TABLE 6 – REQUIREMENTS FOR CONCRETE EXPOSED TO SULFATE-CONTAINING SOLUTIONS
NORMAL DENSITY
AGGREGATE CONCRETE
LOW DENSITY AGGREGATE CONCRETE
SULFATE EXPOSURE
WATER SOLUBLE SULFATE (SO4) IN
SOIL, PERCENT BY MASS
SULFATE (SO4) IN
WATER ppm
CEMENT TYPE MAXIMUM
WATER-CEMENT
RATIO, BY MASS
MINIMUM COMPRESSIVE
STRENGTH f 'c Mpa1)
Negligible 0.00-0.10 0 – 150 -- -- -- Moderate 0.10 – 0.20 150 – 1500 II and I 0.50 25
Severe 0.20 – 2.00 1550 – 10000 V 0.45 30
Very severe Over 2.00 Over 10000 V plus Puzzling3) 0.45 30
1) A Lower water – cement ratio or higher strength may be required for low permeability or for
protection against corrosion of embedded items or freezing and thawing. 2) Seawater. 3) Pozzolan that has been determined by test or service record to improve sulfate resistance
when used in concrete containing Type V cement.
- Air-entraining admixtures shall conform to ASTM C 260-86, "Standard Specification for Air-Entraining Admixtures for Concrete".
- Water-reducing admixtures, retarding admixtures, accelerating admixtures; water
reducing and retarding admixtures and water reducing and accelerating admixtures shall conform to ASTM C 494-86, "Standard Specification for Chemical Admixtures for Concrete".
- Fly Ash or other pozzolan used as admixtures shall conform to ASTM C 618-87,
"Standard Specification for Fly Ash and Raw or claimed Natural pozzolan for Use as a Mineral Admixture in Portland Cement Concrete."
- Ground granulated blast-furnace slag used as an admixture shall conform to "Standard
Specification for Ground Granulated Blast-Furnace Slag for Use in Concrete and Mortars" (ASTM C989-87a).
- The types of admixtures suitable for use in concrete to obtain the desired effect are listed
in Table 6.
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TABLE 7 – ADMIXTURES BY CLASSIFICATION
TYPE OF ADMIXTURE MATERIAL Improve durability Air entraining (ASTM C260) Salts of wood resins
Some synthetic detergents Salts of sulfonated lignin Salts of petroleum acids Salts of proteinaceous material Fatty and resinous acids and their salts Alkyl benzene sulfocates
Reduce water required for given consistency
Water reducer (ASTM C494, Type A)
Lignosulfonates Hydroxylated carboxylic acids (Also tend to retard set so accelerator is added)
Retard setting time Retarded (ASTM C494, Type B)
Lignin Borax Sugars Tartaric acid and salts
Accelerate setting and early strength development
Accelerator (ASTM C494, Type C)
Calcium chloride (ASTM D98) Triethanolamine
Reduce water and retard set
Water reducer and retarded (ASTM C494, Type D)
(See water reducer, Type A, above)
Reduce water and accelerate set
Water reducer and accelerator (ASTM C494, Type E)
(See water reducer, Type A, above. More accelerator is added)
Improve workability and plasticity
pozzolan (ASTM C618)
Natural pozzolan (Class N) Fly ash (Class F and G) Other materials (Class S)
Cause expansion on setting Gas former Aluminum power Resin soap and vegetable or animal glue Saponin Hydrolyzed
Decrease permeability Damp proofing and waterproofing agents
-Separate of calcium, aluminum, ammonium, or butyl -Petroleum greases or oils Soluble chlorides
Improve pump ability Decrease air content
Pumping aids Air detrained
Pozzolans Organic polymers Tribal phosphate
High flow Super politicizes -Suffocated melamine formaldehyde condensates -Suffocated naphthalene formaldehyde condensates
- For place ability, finish ability, abrasion resistance, and durability in flatwork, with regard to aggregate size, the quantity of cement to be used should be not less than shown in Table 8.
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TABLE 8 - MINIMUM CEMENT REQUIREMENTS FOR CONCRETE USED IN FLATWORK
MAXIMUM SIZE OF AGGREGATE, mm
CEMENT. Kg/M3
28 282 25 312 19 324
12.5 354 9.2 366
- The minimum cement content of concrete mixtures exposed to freezing and thawing in the presence of deicing chemicals shall be 252 kg of cement meeting ASTM C 150 or C 595 per m3 of concrete.
- The water-cement ratio required in Tables 4 and 7 shall be calculated using the mass of
cement meeting ASTM C 150 or C 595 plus the weight of fly ash or pozzolan meeting ASTM C 618 and/ or slag meeting ASTM C 989, if any.
12. PLACING
12.1 Conveying
- Concrete shall be handled from the mixer to the place of final deposit as rapidly as
practicable by method, which will prevent separation, or loss of ingredient and in manner which will assure that the required quality of the concrete is obtained.
- Conveying equipment shall be of size and design to insure a continuous flow of
concrete at the delivery end and must be approved by the Employer.
- Chutes shall be metal-lines and shall have a slope not exceeding 1 vertical to 2 horizontal and not less than 1 vertical to 3 horizontal. Chutes more than 6 m long and chutes not meeting the slope requirements may be used provided they discharge into a hopper before distribution.
12.2 Depositing
- Concrete shall be deposited continuously, or in layers of such thickness that no
concrete will be deposited on concrete which has hardened sufficiently to cause the formation, of seams or planes of weakness within the section. If a section cannot be placed continuously, construction joints shall be located at points as provided for in the drawing or as approved by the owner. Placing shall be carried on at such a rate that the concrete which is being integrated with fresh concrete is still plastic.
- Placing of concrete in supported elements such as beams or slabs shall not be started
until the concrete previously placed in columns and walls is no longer plastic. - Concrete shall be deposited as nearly as practicable in its final position to avoid segregation
due to re-handling or flowing. Concrete shall not be subjected to any procedure which will cause segregation.
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- All concrete shall be consolidated by vibration, spading rodding, or forking so that the concrete is thoroughly worked around the reinforcement, around embedded items, and into corners of forms, eliminating all air or stone pockets which may cause honeycombing, pitting, or planes of weakness. Mechanical vibrators shall have a minimum frequency of 7,000 revolutions per minute and shall be operated by competent workmen. Over vibrating and use of vibrators to transport concrete within forms shall not be allowed. Vibrators shall be inserted and withdrawn at many points, from 45 cm to 75 cm apart, for 5 to second duration. Ample stand by vibrators shall be kept on the jobsite during all concrete placing operations.
- Placing of concrete shall be done in such a manner as to prevent overloading any portion of
the formwork.
12.3 Placing Temperature
- Cold weather – When the mean daily temperature falls below 4.5 ْ C (40 F), recommendations as outlined in "Recommended Practice for Cold Weather Concreting" (ACI 306-78) shall apply.
- Hot weather – Concrete deposited in hot weather shall have a placing temperature which
will not cause difficulty from loss of slump, flash set, or cold joints – usually somewhat less than 32 ْ c (90 ْ F). When placing concrete in hot weather recommendations as outlined in "Recommended Practice for Hot Weather Concreting (ACI 305-72) shall apply.
12.4 Bonding - When specified, the surface of joints shall be prepared in accordance with paragraph
7.1.5 - The hardened concrete of joints between footings and walls or columns, between walls
or columns and beams or floors they support, joints in unexposed walls, and all others not mentioned below shall be dampened (but not saturated) immediately prior to placing of fresh concrete.
- The hardened concrete of joints in exposed work, joints in the middle of beams, girders,
joists and slabs and joints in work designed to contain liquids shall be dampened (but not saturated), then thoroughly covered with a coat of neat cement mortar of similar proportions to the mortar in the concrete. The mortar shall be as thick as possible on vertical surfaces and at least 12 mm thick on horizontal surfaces. The fresh concrete shall be placed before the mortar has attained its initial set.
- Joints receiving an adhesive must have been prepared and adhesive applied in
accordance with the manufacturer's recommendations prior to placing of fresh concrete.
- Surfaces must be prepared in accordance with the manufacturer's recommendation prior to placing of fresh concrete.
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13. FINISHING
13.1 Formed Concrete All voids shall be filled and all form ridges and other projections removed. Exposed
concrete shall be rubbed with a carborundum brick or any other similar material approved by the Employer, and a thin cement grout to produce true, even finished surfaces.
13.2 Flat Work Floor slabs, unless otherwise noted, shall be screeded level, tamped with a grid tamper
until a thin bed of grout forms on the surface, and then power-floated and finished as specified on the drawings.
- Floor slabs schedules to receive ceramic tile. Terrazzo or other grouted finished shall
be screened to required elevations, broomed and left rough. - Floor slabs of machine rooms, control rooms compressor and boiler rooms where no
floor covering is required, shall be finished as described for standard finish, and in addition shall be steel-toweled by hand to a hard, dense burnished finish and treated with a zinc fluosilcate-based chemical liquid hardener made by a recognized manufacturer of this type of product. It shall be applied in quantities and by methods as recommended by the manufacturer.
13.3 Finlshed Concrete Surfaces
- All finished concrete surfaces of the same classification shall have the same texture throughout the project.
14. CURING
14.1 General
Freshly deposited concrete shall be protected from premature drying and excessively hot or cold temperatures, and shall be maintained without drying at a relatively constant temperature for the period of time necessary for the hydration of the cement and proper hardening of the concrete.
14.2 Initial Curing
Initial curing shall immediately follow the finishing operation. Concrete shall be kept continuously moist for at least 72 hours. One of he following materials or methods shall be used.
- Pounding or continuous sprinkling by soaker hoses.
- Sand or other covering kept continuously wet by soaker hoses.
- Continuous steam not exceeding 65 ْC (150 ْF), or vapor mist bath.
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- Curing compounds conforming to "Specification for Liquid Membrane-Forming Compounds for Curing Concrete" (ASTM C309-81). Such compounds shall be applied in accordance with the recommendations of the manufacturer and shall not be used on any surfaces against which a additional concrete or other cementations finishing materials are to be bonded, nor on surfaces on which such curing is prohibited by the project specification. Some of these compounds contain a dye and care should be taken to ensure that it does not mar the finished surface.
14.3 Final Curing
Immediately following the initial curing and before the concrete has dried, additional curing shall be accomplished by one of the following materials or methods:
- Continuing the method used in initial curing for four days.
- Waterproof paper conforming to "Specifications for Sheet materials for Curing
concrete" (ASTM C171-87).
- Other moisture-retaining coverings as approved by the Employer.
14.4 Duration of Curing The final curing shall continue until the cumulative number of days or fractions the roof, not necessarily consecutive, during which temperature of the air in contact with the concrete is above 10 ْ C (50 ْ F) has totaled seven (7) days. If high early strength concrete has been used, the final curing shall continue for a total of three (3) days. Rapid drying at the end of the curing period shall be prevented.
14.5 Formed Surface
Steel forms heated by the sun and all wood forms in contact with the concrete during the final curing period shall be kept wet. If forms are to be removed during the curing period, one of the curing methods in paragraph 11.3 shall be employed immediately. Such curing shall be continued for the remainder of the curing period.
15. GROUTING AND DRY PACKING
15.1 Placing grouted and dry Packed Items The Contractor shall the roughly clean all concrete bearing areas by chipping off the
top skin of poor concrete (3 mm is usually sufficient) and wire brushing for removal f all loose material before the plates are set. All equipment bed and slide plates will be furnished and set by Contractor.
15.2 Grouting Grout is mixture of cement and sand with pouring consistency, and its use shall be limited only to such pumps or machine bed plates where placing must be done through holes and where dry packing becomes impractical. In such grout mixtures the water content shall be limited to 22 liters per 50 kg. sack (five U.S gallons per 94 pound sack) of cement, and the mix shall consist of one part of Portland cement and two parts of sand by volume thoroughly mixed.
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15.3 Dry Packing Dry pack is a mixture of one part of Portland cement and three parts of sand by volume mixed thoroughly with just enough water so as to produce a consistency such that when a sample of the dry pack is squeezed in the hand only enough moisture will come to the surface to moisten the hand. Dry packing is accomplished by ramming the dry pack mixture into place.
15.4 Sandused in grouting
- Sand used in grouting shall conform to "Specification for Aggregate for Masonry
Mortar" (ASTM C 144-87) except that gradation may be modified as necessary to obtain proper workability.
15.5 Temperatvre grouting
- Temperature of members at the time of grouting must be above 10 ْC (50 ْF) and this temperature shall be maintained for at least 43 hours.
16. TESTING
- At least 24 hours before any concrete pour the Contractor shall furnish to the Employer a
signed certification for each pour containing the items listed below:
16.1 Quantity of concrete
16.2 Quantities of materials used:
fine aggregate (sand), coarse aggregate (gravel), cement, surface water and total added water.
16.3 Time batching and mixing begins. 16.4 Routine Testing Materials
Routine testing of materials, of proposed mix designs, and of resulting concrete for
compliance with technical requirements of the specifications shall be the duty of the testing agency designated by the Contractor and approved by the Employer and will be performed without expense to the Employer.
16.5 Testing required Testing required because of changes in materials or proportions of the mix requested by
the Employer as well as any extra testing of concrete or materials occasioned by their failure to meet specification requirements, shall be at the Contractor's expense. All rejected materials shall be removed from the construction site without delay.
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16.6 Responsibilities and duties of the Contractor.
- To facilitate testing services the contractor shall:
a) Secure and deliver to the Employer or the testing agency, without cost, preliminary representative samples of the materials he proposes to use and which are required to be tested.
b) Submit through the testing agency to the Employer the concrete mix design he proposes to use, and make written request for approval.
c) Furnish such causal labor as is necessary under the direction of the testing agency to obtain and handle samples at the project or at other sources of materials.
d) Advise the testing agency sufficiently in advance of operations to allow for completion of quality tests and for the assignment of personnel.
e) Provide and maintain for the sole use of the testing agency adequate facilities for safe storage proper curing of concrete test cylinders on the project site for the first 24 hours, as required by ASTM C31-88.
f) Furnish copies of mill test reports of al shipments of cement to the owner and the testing agency, if required.
g) Necessary control test carried out by testing agency shall be performed using standard test equipment.
16.7 Testing of Concrete
Testing shall include compressive tests of molded concrete cylinders, and slump tests for consistency.
- Compressive test cylinders shall be prepared in sets of three cylinders for all tests.
Specimens for each set shall be obtained at the same time and from the same batch of concrete. Tests shall be made for each 60 cubic meter pour or portion thereof. There shall be at least one test (3 specimens) for each day's concreting. The Employer may require a reasonable number of additional tests during the progress of the work.
- Samples from which compression test specimens are molded shall be secured in
accordance with "Method of Sampling Fresh Concrete" (ASTM C172-82). Specimens made to cheek the adequacy of the proportions for strength of concrete or as a basis for acceptance of concrete shall be made and laboratory cured in accordance with "Method of Making and Curing Concrete Compression and Flexure Test Specimens in the Field". (ASTM C31-88a).
- Each set of cylinders shall be tested as follows. One cylinder at 7 days and two cylinder
at 28 days. The forth cylinder shall be retained as a spare, to be tested at 14 days if the 7 day cylinder test was below 50%, of the specified 28 day strength.
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- Tested concrete for all structural units shall meet the following requirements: a) The average of any three laboratory cured 28 days tests of consecutively taken sets
of cylinders for that unit shall equal or exceed the specified 28 days strength, f'c. b) Not more than 10 percent of the 28 day tests shall have values less than the
specified 28 days strength, f'c. c) Not individual strength test result should fall below the specified strength by more
than 35 kg/cm2.
16.8 Slump Eest - Slump tests shall be made according to "Method of Test for Slump of Portland Cement
Concrete". ASTM C143-78a. At least one slump test shall be made each time compression test specimens are taken.
16.9 Concretein Place
- Concrete "in place" that has not met the requirements of the specification in all respects shall be removed and replaced as required. All costs involved in the removal and replacement of such rejected concrete shall be borne by the Contractor.
16.10 Records
Test cylinder sets shall be dated and numbered consecutively. Each cylinder of each set shall also be given and identifying letter and the following data shall be recorded at the time the cylinders are prepared:
- Location of concrete on the job.
- All items specified in the concrete certification, paragraph 13.1
- Maximum size of aggregate.
- Slump.
- Air temperature at time of pour.
- Concrete temperature (if heated concrete is used in clod weather).
- Date poured. - Required age at time of test.
- Name of inspector making cylinders.
- Reports
Copies of reports of cylinder tests, together with the data recorded when preparing those cylinders, shall be air mailed or delivered to the Employer.
17. CONCRETE PAVING
The type of concrete paving shall be as follows: Heavy duty type like crane access/working area. Medium duty type like vehicle access area including under piperacks.
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Light duty type like except the above. The details of each type of paving shall be as shown on standard drawing SD-00-1005-1/1.
17.1 Scope and reference Scope: the present design criteria cover general requirements for the design of concrete paving. Reference: "Concrete pavement design for roads and streets carrying all classes of traffic", published by Portland Cement Association.
17.2 Sub base requirements Sub base shall have a California Bearing Ration (C.B.R.) of not less than 25%.
17.3 Concrete Paving Requirements (1) Concrete paving in general is adopted in entire process areas.
(2) Contraction joints in paved area shall not be more than 16-20 m apart with a maximum
area of about 432 m2 and shall extend to the full depth of the concrete slab. They shall be filled for 6 mm in width and 30 mm in depth with a suitable, hydrocarbon resistant, not extruding material.
In correspondence of contraction joints dowel bars shall be foreseen to transfer at least 20% of the load across the joint to ensure collaboration between the two parts. Half length of the dowel bars shall be oiled to prevent bond with the concrete.
(3) Construction joints shall not be more than 12 m apart and shall extend to the full depth
of the slab. They shall be filled for 6 mm in width and 30 mm in depth with a suitable, hydrocarbon resistant, not extruding material.
The reinforcement shall be continuous, or equivalent tie bars shall be provided.
(4) Dummy joints or control joint in paved area shall not be more than 6 m apart. They shall be 6 mm wide and 30 mm deep and filled with a suitable, hydrocarbon resistant, not extruding material. The cut in concrete shall be made after casting.
(5) Concrete paving shall be separated from all foundation piers above grade by 6 mm thick
resilient jointing material and sealed with a suitable, hydrocarbon resistant, not extruding material and also not flammable.
(6) Paving in areas liable to the spillage of either caustic or acid solutions shall be curbed
and properly proofed.
(7) Curbs, where required, to retain spilled material shall generally by 150 mm high x 100 mm wide, reinforced and cast integrally with paving.
(8) Concrete paving may bear small equipment (small pumps, skid mounted package) with
local strengthening limited to 50 KN/m2.
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18. INSPECTION
- The Employer reserves the right of inspection of the work by its representative during all
phases of concrete work. - The Contractor shall keep a competent superintendent or foreman upon the work, fully
authorized to act for him and to receive such orders as may be given for proper continuance of the work.