Steel Rebars,Deformed Steel Bars,Building Material China Manufacturer Deformed Steel Rebar/Rebar Steel/Iron Rod for construction

SECTION 032000 – concrete REINFORCING

PART 1 - GENERAL

1.1                  SUMMARY

A.            Related Documents:

1.            Drawings and general provisions of the Subcontract apply to this Section.

2.            Review these documents for coordination with additional requirements and information that apply to work under this Section.

B.            Section Includes:  Concrete reinforcement and accessories.

C.           Related Sections:

1.            Division 01 Section "General Requirements."

2.            Division 01 Section "Special Procedures."

1.2                  REFERENCES

A.            General:

1.            The following documents form part of the Specifications to the extent stated. Where differences exist between codes and standards, the one affording the greatest protection shall apply.

2.            Unless otherwise noted, the referenced standard edition is the current one at the time of commencement of the Work.

3.            Refer to Division 01 Section "General Requirements" for the list of applicable regulatory requirements.

B.            ACI – American Concrete Institute:

1.            ACI 117               Tolerances for Concrete Construction

2.            ACI 301               Specifications for Structural Concrete

3.            ACI 315               Standard Practice for Detailing Reinforced Concrete Structures

C.           ASTM International:

1.            ASTM A185 / A185M       Standard Specification for Steel Welded Wire Reinforcement, Plain, for Concrete

2.            ASTM A615 / A615M       Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement

3.            ASTM A706 / A706M       Standard Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement

4.            ASTM A970 / A970M       Standard Specification for Headed Steel Bars for Concrete Reinforcement

D.           CRSI - Manual of Standard Practice.

E.            ICBO - Evaluation Reports.

1.3                  SUBMITTALS

A.            Submit under provisions of Division 01 Section "General Requirements."

B.            Shop Drawings:  Prepare placing drawings in accordance with ACI 315.  Show size, shape and location of bars and wire fabric in structure.  Show splice locations and lengths.  Where details are not shown, conform to standards of practice indicated in ACI 315 and submit for approval.

1.            Bill reinforcing bars for walls on elevations.  Bill reinforcing bars for slabs on plans.  Plans and elevations need not be true views.  When more than one wall or slab are identical, only one such wall or slab is required.  Take sections to clarify the arrangement of reinforcement.  Identify, but do not bill bars on sections.

1.            Unless the location of reinforcing is clear, give dimensions to some structural feature that will be readily distinguishable at time bars are placed.

2.            Make placing drawings complete, including the location of support bars and chairs, without reference to the design drawings.

B.            Submit data required to evaluate proposed mechanical splices.

C.           Submit manufacturer's certified mill test reports on each heat of reinforcing steel delivered, showing physical and chemical analysis before placing reinforcement.

D.           LEED Submittals:

<Retain subparagraph below if recycled content is required for LEED-NC or LEED-CI Credits MR 4.1 and MR 4.2.  An alternative method of complying with Credit MR 4.1 and MR 4.2 requirements is to retain requirement in Division 01 Section "Sustainable Design Requirements" that gives Contractor the option and responsibility for determining how Credit MR 4.1 and MR 4.2 requirements will be met.>

1.            Product Data for Credit MR 4.1[ and Credit MR 4.2 ]:  For products having recycled content, documentation indicating percentages by weight of postconsumer and preconsumer recycled content.

a.            Include statement indicating costs for each product having recycled content.

1.2                  QUALITY ASSURANCE

A.            Codes and Standards:  Comply with provisions of ACI 301 CRSI's "Manual of Standard Practice", except where more stringent requirements are shown or specified.

B.            Requirements of Regulatory Agencies:  Proprietary products, including bar couplers, shall have an active ICBO Evaluation Report.

C.           Material Quality Assurance:  Mill test reports including chemical analysis, tensile properties and bend test shall be examined for all reinforcing.  Conform to one of the following:

D.           Maintain positive identification of reinforcing by heat number.  Provide certified mill test reports to Testing Laboratory.

E.            Where positive identification cannot be made and procedures are not deemed adequate to ensure compliance, Testing Laboratory will randomly sample and make one tensile and one bend test from each 2-1/2 tons or fraction thereof of each size of reinforcement.  Subcontractor will bear the cost of testing.

PART 2 - PRODUCTS

2.1                  REINFORCING MATERIALS

A.            Bar Reinforcement: ASTM A615, Grade 60, deformed billet bars.

1.            ASTM A706, where noted on Drawings.

2.            Recycled content shall be a minimum of 75 percent recycled post consumer steel.

B.            Headed Bar Reinforcement:  ASTM A970.

C.           Spirals: ASTM A82.

D.           Welded Wire Fabric: ASTM A185.

E.            Threaded Bars: Grade 75, manufactured by DYWIDAY Systems International, Williams Form Engineering Corp. or equal substituted per Division 1.

F.            Smooth Dowels, ASTM A615, Grade 40 or 60, smooth; sawcut or grind one end to remove offsets; shop paint with iron oxide zinc chromate primer.

G.           Welded Deformed Bar Anchors: ASTM A-108 f _y = 70,000 psi, flux-filled deformed bar anchors welded to structural steel as shown; Nelson D2L, or equal substituted per Division 1.

H.           Mechanical Bar Couplers:  Provide mechanical couplers with a current ICC evaluation report. Coupler shall  develop 160% percent of specified minimum yield strength of spliced reinforcement.  Subject to compliance with requirements provide one of the following, or approved equal:

1.            Barteck, Dextra Inc.

2.            Lenton Taper Threaded Connection, Erico Inc.

3.            Bar Lock, Dayton Superior Inc.

2.2                  ACCESSORIES

A.            Tie Wire: Minimum 16-gage black annealed wire.

B.            Bar Supports:

1.            At surfaces not exposed to view in completed structure:  Precast concrete bar supports with two 16 ga. embedded wires or CRSI Class 2 wire supports.

2.            Supports placed against ground or on top of vapor barrier:  Precast concrete blocks not less than 3 inches square (1935 mm²) with two 16 ga. embedded wires.

3.            At Architectural Concrete and surfaces exposed to weather:  CRSI Class 2 stainless steel or CRSI Class 1 plastic protected.

4.            Where support is no closer to concrete surface than 1/2 inch (13 mm):  CRSI Class 3 wire supports.

2.3                  FABRICATION

A.            Fabricate reinforcement in accordance with ACI 315 where specific details are not shown.

PART 3 - EXECUTION

3.1                  PLACEMENT

A.            Surface Condition of Reinforcement: Before placing concrete, clean reinforcement of loose scale, dirt, grease and other substances which would impair bond with concrete.

B.            Place reinforcement in accordance with the Drawings and the CRSI Manual.

1.            Steel bars shall be of size and length indicated, accurately bent or formed to shapes detailed or scheduled by experienced shops by methods that will not injure the materials.  Reinforcing bars shall be shop fabricated to lengths and bends shown on the drawings.  Fabrication tolerance shall be in accordance with the requirements of ACI 315.

2.            Reinforcing bars shall be as long as possible with a minimum number of joints.

3.            Steel reinforcement shall not be bent or straightened in a manner that will injure the material or the embedding concrete.  Bars with kinks or bends not shown on the Drawings shall not be used.  Heating of reinforcement for bending will not be permitted.

4.            Reinforcement shall be tagged with suitable identification to facilitate sorting and placing.

C.           Place reinforcing bars accurately as to spacing and clearance and securely tied at intersections and supports with wire and in such a manner as will preclude displacement during pouring of concrete.  Placing tolerances shall be in conformance with the requirements of ACI 117.

D.           Place and secure reinforcement to maintain the proper distance and clearance between parallel bars and from the forms.  Provide vertical steel with metal spreaders to maintain steel properly centered in the forms.  Horizontal reinforcement shall be supported at proper height on concrete pads, chairs or transverse steel bars.

E.            After placing, maintain bars in a clean condition until completely embedded in concrete.

F.            Bars shall not be spaced closer than 1-1/2 diameters of the largest of two adjacent bars, 1-1/2 times the maximum aggregate size, nor one inch, except at bar laps.  Where reinforcement in members is placed in two layers, the clear distance between layers shall be not less than one inch (25 mm) or more than 1-1/2 inches (13 mm) unless otherwise noted on the drawings.  The bars in the upper layer shall be placed directly above those in the bottom layer unless otherwise detailed.

G.           Coverage of bars shall be as shown and scheduled.  Conform to ACI 301 where not indicated.

H.           Where obstruction prevents the intended placement of reinforcement, provide additional reinforcement as directed by the University around the obstruction.

I.              Splice bars as indicated by lapping and securely wiring together.  Splices at locations other than those indicated are subject to the approval of the University.  Splices of reinforcement shall not be made at the point of maximum stress.  Splices shall provide sufficient lap to transfer the stress between bars by bond and shear.  Bars shall be spread the minimum distance specified.  Stagger splices of adjacent bars where possible.

J.            Reinforcing bars shall not have welded joints.

K.            Mechanical Bar Couplers:  Install in accordance with applicable ICC evaluation report.  Maintain clearance and coverage at coupler.  Stagger couplers wherever practical.

3.2                  FIELD INSPECTION

A.            University Testing Laboratory will:

1.            Review Quality Assurance procedures for maintaining identification of steel. Collect certificates of compliance and test reports for reinforcing steel.

2.            Special Inspect placement of reinforcement for conformance with the Contract Documents and as required by CBC Chapter 17.

3.            Special Inspect installation of mechanical couplers in accordance with requirements of applicable ICC evaluation report.

4.            Special Inspect shop and field welding as required by CBC Chapter 17