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SECTION 03 30 00 - CAST-IN-PLACE CONCRETE FOR EXTERIOR WALKWAYS & CURBING

PART 1 - GENERAL

  1.1                  SUMMARY

 Section includes cast-in-place concrete, including formwork, reinforcement, concrete materials, mixture design, placement procedures, and finishes.

1.2                  ACTION SUBMITTALS

1. Product Data: For each type of product indicated.

1. LEED Submittals (if applicable to project):

1. Product Data for Credit MR 4: For products having recycled content, documentation indicating percentages by weight of postconsumer and preconsumer recycled content. Include statement indicating cost for each product having recycled content.
2. Product Data for Credit IEQ 4.3: For curing and sealing compounds, documentation including printed statement of VOC content.
3. Design Mixtures for Credit ID 1.1: For each concrete mixture containing fly ash as a replacement for portland cement or other portland cement replacements, and for equivalent concrete mixtures that do not contain portland cement replacements.

1. Design Mixtures: For each concrete mixture.

1. Steel Reinforcement Shop Drawings:   Placing drawings that detail fabrication, bending, and placement.

1.3                  INFORMATIONAL SUBMITTALS

1. Welding certificates.

1. Material certificates.

1. Material test reports.

1.4                  QUALITY ASSURANCE

1. Manufacturer Qualifications: A firm experienced in manufacturing ready-mixed concrete products and that complies with ASTM C 94/C 94M requirements for production facilities and equipment.

1. Manufacturer certified according to NRMCA's "Certification of Ready Mixed Concrete Production Facilities."

1. Installer Qualifications: An experienced installer who has completed concrete work similar in material, design, and extent to that indicated for this project and whose work has resulted in construction with a record of successful in-service performance.

1. Welding Qualifications: Qualify procedures and personnel according to AWS D1.4/D 1.4M, "Structural Welding Code - Reinforcing Steel."

1. ACI Publications: Comply with the following unless modified by requirements in the Contract Documents:

1. ACI 301, "Specifications for Structural Concrete," Sections 1 through 5.
2. ACI 117, "Specifications for Tolerances for Concrete Construction and Materials."

1. Preinstallation Conference: Conduct conference at Project site. PART 2 - PRODUCTS

2.1                  GENERAL

1. ACI Publications: Comply with the following unless modified by requirements in the contract documents:
   1. ACI 301

2.       ACI 303.1

2.2                  STEEL REINFORCEMENT

1. Recycled Content of Steel Products: Postconsumer recycled content plus one-half of preconsumer recycled content not less than 25 percent.

1. Reinforcing Bars: ASTM A 615, Grade 60 (Grade 420), deformed.
   1. Epoxy-Coated Reinforcing Bars:  ASTM A 775, epoxy coated, with less than 2 percent damaged coating in each 12-inch (300-mm) bar length.

1. Plain-Steel Welded Wire Reinforcement: ASTM A 185, plain, fabricated from as-drawn steel wire into flat sheets.

1. Deformed-Steel Welded Wire Reinforcement: ASTM A 497, flat sheet.

1. Bar Supports: Bolsters, chairs, spacers, and other devices for spacing, supporting, and fastening reinforcing bars and welded wire reinforcement in place. Manufacture bar supports from steel wire, plastic, or precast concrete according to CRSI's "Manual of Standard Practice.

2.3    CONCRETE MATERIALS

1. Cementitious Material: Use the following cementitious materials, of the same type, brand, and source, throughout Project:

1. Portland Cement: ASTM C 150, Type I/II. Supplement with the following:

1. Fly Ash: ASTM C 618, Class F or C.
2. Ground Granulated Blast-Furnace Slag: ASTM C 989, Grade 100 or 120.

1. Normal-Weight Aggregates: ASTM C 33, graded.

1. Maximum Coarse-Aggregate Size: per ACI 318.
2. Fine Aggregate: Free of materials with deleterious reactivity to alkali in cement.

1. Water: ASTM C 94 and potable.

2.4                  ADMIXTURES

1. Air-Entraining Admixture: ASTM C 260.

1. Chemical Admixtures: Provide admixtures certified by manufacturer to be compatible with other admixtures and that will not contribute water-soluble chloride ions exceeding those permitted in hardened concrete. Do not use calcium chloride or admixtures containing calcium chloride.

1. Water-Reducing Admixture: ASTM C 494, Type A.
2. Retarding Admixture: ASTM C 494, Type B.
3. Water-Reducing and Retarding Admixture: ASTM C 494, Type D.
4. High-Range, Water-Reducing Admixture: ASTM C 494, Type F.
5. High-Range, Water-Reducing and Retarding Admixture: ASTM C 494, Type G.
6. Plasticizing and Retarding Admixture: ASTM C 1017, Type II.

2.5                  FIBER REINFORCEMENT

1. Synthetic Micro-Fiber: Monofilament or fibrillated polypropylene micro-fibers engineered and designed for use in concrete, complying with ASTM C 1116, Type III, 1/2 to 1-1/2 inches (13 to 38 mm) long.

2.6                  CURING MATERIALS

1. Clear, Solvent-Borne, Membrane-Forming Curing and Sealing Compound: ASTM C 1315, Type 1, Class A.

1. VOC Content:  Curing and sealing compounds shall have a VOC content of 200 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24).

1. Clear, Waterborne, Membrane-Forming Curing and  Sealing  Compound:  ASTM C 1315, Type 1, Class A.

1. VOC Content:  Curing and sealing compounds shall have a VOC content of 200 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24).

2.10               CONCRETE MIXING

1. Ready-Mixed  Concrete:  Measure,  batch,  mix,  and  deliver   concrete   according   to ASTM C 94 and ASTM C 1116, and furnish batch ticket information.

1. When air temperature is between 85 and 90 deg F (30 and 32 deg C), reduce mixing and delivery time from 1-1/2 hours to 75 minutes; when air temperature is above 90 deg F (32 deg C), reduce mixing and delivery time to 60 minutes.

1. Project-Site Mixed Concrete: Measure, batch, and mix concrete materials and concrete according to ASTM C 94. Mix concrete materials in appropriate drum-type machine mixer.

PART 3 - EXECUTION

3.1                  FORMWORK

1. Design, erect, shore, brace, and maintain formwork, according to ACI 301, to support vertical, lateral, static, and dynamic loads, and construction loads that might be applied, until structure can support such loads.

1. Construct formwork so concrete members and structures are of size, shape, alignment, elevation, and position indicated, within tolerance limits of ACI 117.

3.2                  EMBEDDED ITEMS

1. Place and secure anchorage devices and other embedded items required for adjoining work that is attached to or supported by cast-in-place concrete. Use setting drawings, templates, diagrams, instructions, and directions furnished with items to be embedded.

3.3                  STEEL REINFORCEMENT

1. General: Comply with CRSI's "Manual of Standard Practice" for placing reinforcement.

3.4                  JOINTS

1. General: Construct joints true to line with faces perpendicular to surface plane of concrete.

1. Construction Joints: Install so strength and appearance of concrete are not  impaired,  at locations indicated or as approved by Owner. Install slip dowels to prevent differential vertical displacement, yet allow for horizontal movement of the joint.

1. Contraction Joints in Slabs-on-Grade: Form weakened-plane contraction joints, sectioning concrete into areas as indicated. Construct contraction joints for a depth equal to at least one- fourth of concrete thickness as follows:

1. Grooved Joints: Form contraction joints by grooving and finishing each edge of joint to a radius of 1/4 inch (3.2 mm). Repeat grooving of contraction joints after applying surface finishes. Eliminate groover tool marks on concrete surfaces.

1. Isolation Joints in Slabs-on-Grade: After removing formwork, install joint-filler strips at slab junctions with vertical surfaces, such as column pedestals, foundation walls, grade beams, and other locations, as indicated.

3.5                  CONCRETE PLACEMENT

1. Before placing concrete, verify that installation of formwork, reinforcement, and embedded items is complete and that required inspections have been performed.

1. Deposit concrete continuously in one layer or in horizontal layers of such thickness that no new concrete will be placed on concrete that has hardened enough to cause seams or planes of weakness. If a section cannot be placed continuously, provide construction joints as indicated. Deposit concrete to avoid segregation.

1. Consolidate placed concrete with mechanical vibrating equipment according to ACI 301.

1. Screed and initial-float concrete floors and slabs using bull floats or darbies to form a uniform and open-textured surface plane, free of humps or hollows, before excess moisture or bleedwater appears on the surface. Do not further disturb slab surfaces before starting finishing operations.

1. Cold-Weather Placement: Comply with ACI 306R.

1. Hot-Weather Placement: Comply with ACI 305R.

3.6                  FINISHING

1. General: Comply with ACI 302.1R recommendations for screeding, restraightening, and finishing operations for concrete surfaces. Do not wet concrete surfaces.

1. Broom Finish: Apply a broom finish to concrete by brooming with fiber-bristle broom perpendicular to main traffic route, to platforms, steps, ramps, walkways and elsewhere as indicated.

3.7                  CONCRETE PROTECTING AND CURING

1. General: Protect freshly placed concrete from premature drying and excessive cold or hot temperatures. Comply with ACI 306.1 for cold-weather protection and ACI 301  for  hot- weather protection during curing.

1. Evaporation Retarder: Apply evaporation retarder to unformed concrete surfaces if hot, dry, or windy conditions cause moisture loss approaching 0.2 lb/sq. ft. x h (1 kg/sq. m x h) before and during finishing operations. Apply according to manufacturer's written instructions after placing, screeding, and bull floating or darbying concrete, but before float finishing.

1. Begin curing after finishing concrete but not before bleed water has disappeared from concrete surface. Cure concrete according to ACI 308.1 by the following method:

1. Curing and Sealing Compound: Apply uniformly to floors and slabs indicated in a continuous operation by power spray or roller according to manufacturer's written instructions while concrete surface is still moist.  Recoat areas subjected to heavy rainfall within three hours after initial application. Repeat process and apply a second coat at a right angle to the first coat. Maintain continuity of coating and repair damage during curing period.

3.8                  CONCRETE SURFACE REPAIRS

1. Defective Concrete: Repair and patch defective areas when approved by Owner. Remove and replace concrete that cannot be repaired and patched to Owner's approval.

3.9                  FIELD QUALITY CONTROL

1. Testing and Inspecting: Owner will engage a qualified testing and inspecting agency to sample materials, perform tests, and submit test reports during concrete placement. Tests shall be performed according to ACI 301.

3.10               CONCRETE CURB

1. The following specifications and standards of the issues listed are to be utilized:
2. Commonwealth of Pennsylvania Department of Transportation Specifications, Publication 408 and Supplements, latest edition, hereinafter referred to as Pub. 408.
3. American Society of Testing Materials (ASTM).

1. All concrete curb work shall be constructed in conformance with the latest edition Pub. 408, Section 630, as noted and amended herein:
2. Concrete mix design as per Section 2.8(D) of this specification.
3. Curb shall be a monolithic pour with form or saw contraction joints 3/16-inch wide and 2 inches deep.
4. Contraction joints shall be spaced at 4’ minimum and 20’ maximum.
5. Concrete curb may be placed with an acceptable, self-propelled machine as approved by the University and in accordance with Pub. 408, Section 630.3(d). Comply with all curb profiles and dimensions.
6. Use acceptable metal forms as per Section 501.3(d). Wood forms may be used on sharp curves as detailed in Section 501.3(d).
7. Match curb profiles where new work is an extension or revision of existing.
8. Construct curb to details shown on plans.

3.11               EXTERIOR CONCRETE WALKWAYS:

1. The following specifications and standards of the issues listed are to be utilized:
2. Commonwealth of Pennsylvania Department of Transportation Specifications, Publication 408 and Supplements, latest edition, hereinafter referred to as Pub. 408.

1. American Society for Testing Materials (ASTM).
2. American Concrete Institute (ACI).
3. American Association of State Highway and Transportation Officials (AASHTO).

1. Before placing aggregate bed for concrete walkway, check the subgrade and do all necessary grading, rolling, and compacting required to attain a true, even, firm surface. Fill and consolidate any traces of dented or depressed areas. Remove all spongy material, replace with suitable earthfill, and compact solidly with roller or mechanical compactors; moisten if required.

1. Provide a 2A crushed aggregate subbase course fully choked and rolled to the compacted thickness indicated on the drawings. Aggregate for subbase course shall be Type C, or better, as specified in Pub. 408, Section 703.2.

1. Joints:
2. Use ¼” thick premolded expansion joint material the specified depth of the concrete slabs along all foundations and walls where slabs abut other fixed structures; longitudinally where sidewalk slab is to be constructed in contact with curb, and adjacent to existing structures as directed.
3. Construction joints shall be located at the discretion of the Contractor accommodating the joint pattern on the drawings. See typical details.
4. Where existing and/or new light standards, poles, fire hydrants, access frames and covers to underground utilities, manhole frames and covers, and similar structures are within the limits of the sidewalk areas, the concrete around such structure shall be scored, by edging and/or grooving, in a block 8” wider than the maximum dimensions of the structure at the sidewalk elevation. Prior to placing the concrete around such structures, premolded expansion joint material shall be placed around the structure to the full depth of the slab.
5. Unless otherwise directed by the University, a metal edger having a ¼” radius shall be used for edging all joints. Transverse and longitudinal scoring shall be done in accordance with the drawings and/or directed.  Scoring and control joints shall extend to a depth of at least ¼ of the thickness of the slab.

1. Forms:
2. Forms may be metal or wood, securely staked and braced, and constructed to true lines and shapes indicated and extending the full depth of the concrete.
3. Forms shall be oiled if metal or wetted or oiled if wood. Form oil shall be an approved form coating. Care shall be taken to prevent reinforcement from becoming coated with form oil.
4. Forms once used shall be thoroughly cleaned before being reused.
5. Side forms shall not be removed within 12 hours after the concrete has been placed. After the removal of forms, minor honeycomb at formed areas shall be filled with mortar composed of 1 part cement and 2 parts fine aggregate. Major honeycomb areas will be considered as defective work, and shall be removed and replaced at no additional cost to the University.

1. Placing Concrete Walkways:
2. All concrete work shall conform to referenced and applicable standards and the latest American Concrete Institute Manual of Concrete Practice.
3. Sidewalk slabs shall be one-course construction of thickness indicated on drawings but in no case less than a full five (5) inches, unless otherwise specified on the drawings.