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HomeMy WebLinkAbout32-13-14-Seashell-Concrete-Paving_Rev_1Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 1 of 14 Section 32 13 14 SEASHELL CONCRETE PAVING PART 1 - GENERAL 1.1 SUMMARY A. Drawings and General Provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section. B. Massachusetts Highway Department (MHD), Standard Specifications for Highways and Bridges, latest Edition with amendments, hereinafter referred to as the “Standard Specifications”. C. Massachusetts Highway Department (MHD), Construction Standards, latest Edition with amendments hereinafter referred to as the “Construction Standards”. D. Related Sections: The following Sections contain requirements that relate to this Section: 1. Section 31 00 00 – Earth Moving 2. Section 32 13 13 – Portland Cement Concrete Pavement 3. Section 01 60 00 - Product Requirements: Listing of Emissions and VOC requirements. 4. Section 01 74 19 - Construction Waste Management and Disposal: Procedural and administrative requirements for construction and demolition recycling 5. Section 01 81 13 - Sustainable Design Requirements: Special administrative and procedure requirements related to Owner’s LEED v4 for Schools Building Design + Construction (BD+C) goals of Certification. 6. Section 01 81 13a - LEED v4 Materials Reporting Form: Materials Tracking for Building Product Disclosure and Optimization credits 1.2 DESCRIPTION OF WORK A. Work included: Provide all labor, materials, equipment, and transportation necessary to complete the placement of concrete. Such work includes, but is not limited to, the following: 1. Tabby Seashell concrete walkways at the locations shown on the Plans and specified herein. 1.3 SUBMITTALS A. General: Refer to Division 01 Submittals provisions and procedures. 1. Provide product data for all materials and items, including reinforcement and forming accessories, aggregates, admixtures, joint systems, curing compounds, sealers and sealants. Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 2 of 14 2. Material Certificates: Provide copies of materials certificates signed by material producer and Contractor, certifying that each material item complies with, or exceeds, specified requirements. 3. Plant mix design for concrete. B. The Contractor shall submit a one (1) gallon sample of the seashells for review and approval by the Landscape Architect. C. The Contractor shall provide a shop drawing indicating pouring sequence based on the Plans. D. The Contractor shall fabricate in the field one sample of the seashell concrete paving in a single pour measuring 10’ long x 5’wide x 4” thick for approval by the Landscape Architect. The sample shall demonstrate the final surface finishes, texture, each joint type, seashell exposure and color that will be provided uniformly throughout the project. 1. If the sample is approved, it may become part of the final work and shall be the basis of workmanship for all other seashell concrete paving. E. Provide all qualification data listed in Section 1.4 of this specification F. LEED Submittals: 1. Provide manufacturers’ product documentation that includes recycled content claims for the products contributing towards compliance. Claims must conform to the definition in ISO 14021-1999, Environmental Labels and Declarations, Self-Declared Environmental Claims. 2. Complete "LEED Materials Documentation Sheet" with MRc3 Option 2 information for products with recycled content installed in the building. 1.4 QUALITY ASSURANCE A. Qualifications: The foreman and labors shall be thoroughly trained and experienced in the skills required to complete seashell paving flatwork, be completely familiar with the design and application of the work, be present at all times during the work and perform the work. The foreman and laborers shall have no less than five years minimum proven experience in the required paving techniques and desired results. Submit list of installations, indicating location, Owner, Architect/Engineer, date of installation, Contractor, and setting bed, for approval by the Architect. 1.5 REFERENCE STANDARDS A. ASTM: American Society for Testing and Material. B. AASHTO: American Association of State Highway and Transportation Officials. C. ACI: American Concrete Institute. D. All ramps and curb ramps shall comply with American Disabilities Act Accessibility Guidelines Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 3 of 14 1.6 TESTING, CONTROL AND INSPECTION A. The Contractor will retain the services of a qualified independent testing agency, approved by the Architect, to test aggregate and to prepare a mix design for each strength of concrete specified; and shall submit such mix designs and test results to the Architect for approval. Mix designs may also be based on proven current designs accompanied by test results. The costs of all such preliminary services shall be borne by the Contractor. 1. Testing equipment will be provided by and tests performed by the testing laboratory. Upon request by the Architect, the testing laboratory shall provide such auxiliary personnel and services needed to accomplish the testing work. 2. Concrete test cylinder tests shall be taken for each 50 cubic yards of concrete placed, but at least one set for each day of concrete placements. 3. Testing required because of changes requested by the Contractor in materials, sources of materials or mix proportions, and extra testing of concrete or materials because of failure to meet the Specification requirements shall be paid by the Contractor. 4. Concrete shall be sampled and tested for quality control as follows: a. Sampling fresh concrete: ASTM C172 b. Concrete test specimens: ASTM C31 c. Slump: ASTM C143. – Slump shall be one to three inches, or five to seven inches with Super plasticizer. d. Air Content: ASTM C231 e. Compressive strength: ASTM C39 – Concrete shall be 4000 psi at 28 days f. Unit Weight: ASTM C29 1.7 NOTIFICATION OF RELATED TRADES A. Notify all other trades responsible for installing chases electrical handholes, conduit, when ready for such installation, and for final checking immediately before concrete is placed. Cooperate with such trades to obtain proper installation. 1.8 PRE-INSTALLATION CONFERENCE A. Installer of the Work of this Section is required to attend pre-installation conference specified under this Specification. B. Contractor shall request in writing an on-site meeting with the Owner’s Representative, the General Contractor and Site Contractor, the Landscape Architect and the Civil Engineer to review the scope of work prior to any work taking place to review the site conditions. Any deficiencies in the site conditions shall be remedied by the Contractor and approved by the Owner prior to commencing any work. PART 2 - PRODUCTS Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 4 of 14 2.1 FORMS A. Form Materials: Plywood, metal, metal-framed plywood, or other acceptable panel-type materials to provide full-depth, continuous, straight, smooth exposed surfaces. 1. Use flexible or curved forms for all radii indicated on the Plans. B. Form Release Agent: Provide commercial formulation form-release agent with a maximum of 350 g/L volatile organic compounds (VOCs) that will not bond with, stain, or adversely affect concrete surfaces and will not impair subsequent treatments of concrete surfaces. 2.2 REINFORCING MATERIALS A. Reinforcing Steel Bars: Shall be newly rolled billet steel conforming to ASTM A615 (Grade 60 unless noted). Bars shall be bent cold. Reinforcing bars being welded shall conform to ASTM A706, Grade 60. B. Joint Dowel Bars: Stainless steel bars, ASTM A955. Cut bars true to length with ends square and free of burrs. C. Welded Wire Mesh shall be welded plain cold-drawn steel wire fabric, ASTM A 185 and shall be supplied in sheets. D. Supports for Reinforcement: Chairs, spacers, dowel bar supports and other devices for spacing, supporting, and fastening reinforcing bars, welded wire fabric, and dowels in place. Use wire bar-type supports complying with CRSI specifications. 1. Use supports with sand plates or horizontal runners where base material will not support chair legs. Concrete bricks may be used to support reinforced steel where application allows. E. Synthetic Reinforcement: Shall not be used for seashell Concrete. 2.3 CONCRETE MATERIALS A. The Contractor shall insure that the final appearance of the sidewalks is consistent throughout the whole project. Any differences in color, texture, or finish will not be accepted by the Landscape Architect. 1. Any portion of sidewalk or walkway that does not match the color, texture, or finish of previously constructed sidewalks will be removed and replaced with a sidewalk that matches the recently poured sidewalks at the expense of the Contractor. B. Portland Cement: ASTM C 150, Type I for resistance to salt and ice melt chemicals. 1. Use one brand of cement throughout Project. C. Seashells: Shall be hard, sound, durable, smooth, and free of all deleterious materials and staining qualities. Sharp, jagged edges will not be accepted. 1. Shells shall be thoroughly washed so that it is free of dust, dirt, and clay Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 5 of 14 particles. 2. All seashells shall be from same source throughout project. 3. Shells - Shell size shall be a range of ¼” to 1”. 4. Shells shall be in a color range of cold and warm tones: tan, gray, blue, white, yellow and buff. D. Water: Shall be from an approved source, potable, clean and free of oils, salts, alkali, organic matter and other deleterious material. 2.4 ADMIXTURES A. Provide concrete admixtures that contain not more than 0.1 percent chloride ions. B. Air-Entraining Admixture: ASTM C 260, certified by manufacturer to be compatible with other required admixtures. C. Water-Reducing Admixture: ASTM C 494, C494M, Type D. D. High-Range Water-Reducing Admixture: ASTM C 494, C494M, Type F E. Water-Reducing and Accelerating Admixture: ASTM C 494, Type E. F. Water-Reducing and Retarding Admixture: ASTM C 494, C494M, Type D. 2.5 CURING MATERIALS A. Absorptive Cover: Burlap cloth made from jute or kenaf, weighing approximately 9oz. per sq. yd., complying with AASHTO M 182, Class 2. B. Moisture-Retaining Cover: One of the following, complying with ASTM C 171. 1. Waterproof paper. 2. Polyethylene film. 3. White burlap-polyethylene sheet. C. Clear Solvent-Borne Liquid Membrane-Forming Curing Compound: ASTM C 309, Type I, Class A or B, wax free. D. Clear Waterborne Membrane-Forming Curing Compound: ASTM C 309, Type I, Class B. 1. Provide material that has a maximum volatile organic compound (VOC) rating of 350g/L. E. Evaporation Control: Monomolecular film-forming compound applied to exposed concrete lab surfaces for temporary protection from rapid moisture loss. F. Contractor shall use the same manufacturer for the curing compound, retarder and sealer. 2.6 CONCRETE ADA ACCESSIBLE CURB CUTS A. Contractor shall install concrete ADA accessible curb cuts at all locations shown on plans. Curb cut configurations shall be as detailed on the Drawings. Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 6 of 14 1. All concrete curb cuts shall be isolated from surrounding concrete pavement when applicable. 2. Curb cuts shall be built with cut curbstone to match concrete curb cut slopes. B. Curb cuts shall not exceed: 1. Cross-slopes at front and back of curb cuts: 1.5% max. 2. Curb cuts: 7.5% max C. All planes of the finished curb cuts shall be field checked for slopes using a two- foot electronic “smart” level. 1. Curb cuts that do not comply with the slope requirements shall be cut out in their entirety and completely rebuilt. 2.9 CHEMICAL SURFACE RETARDER A. Chemical Surface Retarder must be a water-soluble, liquid-set retarder with color dye, for horizontal concrete surface application, capable of temporarily delaying final hardening of concrete depth of 1/8 to ¼ inch. The chemical surface retarder must be approved by the Engineer before beginning construction of sidewalks. B. Contractor shall use the same manufacturer for the curing compound, retarder and sealer. 2.10 CONCRETE SEALER A. Concrete flatwork shall be surface coated with a non-yellowing, non-staining or discoloring silane or siloxane-based sealer designated for finish concrete surfaces. The product must demonstrate the ability to reduce water and salt intrusion or absorption reduction by at least 80%, be VOC compliant, be designed to absorb into the concrete surface, and included on the MassDOT approved materials list for this type of sealing application. Note: Paraffin based coatings or latex based surface coatings, or curing agents shall not be used or approved for this application. B. Contractor shall use the same manufacturer for the curing compound, retarder and sealer. 2.11 JOINTS AND SEALANTS A. Joint Material: Preformed polyethylene foam expansion joint material. Joint material shall be flexible, lightweight, non-staining, polyethylene, closed-cell joint filler. Joint material shall come pre-scored with a removable strip. B. Sealant: Sealant shall be a single component, Type HL1, self-leveling, premium-grade polyurethane sealant. Color shall be approved by the Landscape Architect. 2.12 LEED Requirements Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 7 of 14 A. Wood products that are not reused, salvaged, or recycled must be certified to the standards of the Forest Stewardship Council. B. Provide products manufactured and extracted within 100 miles of the project site whenever possible. C. Provide products with the maximum recycled content possible. Minimum recycled content 20% PART 3 - EXECUTION 3.1 CONCRETE MIX A. Prepare design mixes for each type and strength of normal-weight concrete by either laboratory trial batch or field experience methods as specified in ACI 301. For the trial batch method, use a qualified independent testing agency for preparing and reporting proposed mix designs. 1. Do not use the Owner's field quality-control testing agency as the independent testing agency. B. Proportion mixes according to ACI 211.1 and ACI 301 to provide normal-weight concrete with the following properties: 1. Compressive Strength (28-Day), ASTM C39: 4000 psi. 2. Maximum Water-Cement Ratio at Point of Placement: 0.45. 3. Slump Limit at Point of Placement, ASTM C143: 3 inches maximum. a. Slump limit for concrete containing high-range water-reducing admixture (superplasticizer): Not more than 8 inches after adding admixture to site-verified 2-to-3-inch slump concrete. C. Add air-entraining admixture, ASTM C231, at manufacturer's prescribed rate to result in concrete at point of placement having an air content as follows with a tolerance of plus or minus 1-1/2 percent: 1. Air Content: 5.5 percent for 1-1/2-inch maximum aggregate. 2. Air Content: 6.0 percent for 1-inch maximum aggregate. 3. Air Content: 6.0 percent for 3/4-inch maximum aggregate. 4. Air Content: 7.0 percent for 1/2-inch maximum aggregate. 5. Air Content: 2.5 to 4.5 percent. D. Addition of Synthetic Reinforcement: None. E. Adjustment to Concrete Mixes: Contractor may request to the Architect Mix design adjustments when characteristics of materials, project conditions, weather, test results, or other circumstances warrant. 3.2 CONCRETE MIXING A. Ready-Mixed Concrete shall be mixed and transported in accordance with specification for Ready-Mixed Concrete ASTM C94, Alt. No. 3 and ACI Standard 304, “Recommended Practice for Measuring, Mixing, Transporting and Placing Concrete. Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 8 of 14 3.3 SURFACE PREPARATION A. Proof-roll prepared subbase surface to check for unstable areas and verify need for additional compaction. Do not begin paving work until such conditions have been corrected and are ready to receive paving. Note: Contractor shall confirm that all compaction requirements of the base course have been met. B. Remove loose material from compacted subbase surface immediately before placing concrete. 3.4 INSTALLATION OF EMEDDED ITEMS A. Conform to requirements of ACI 318, Chapter 6 “Conduits and Pipes Embedded in Concrete”, and as specified below. B. Installation if inserts required by other trades shall be coordinated with or shall be installed prior to placing of reinforcing steel. All inserts to be supplied by the respective trade and installed by the General Contractor. 3.5 EDGE FORMS AND SCREED CONSTRUCTION A. Set, brace, and secure edge forms, bulkheads, and intermediate screed guides for paving to required lines, grades, and elevations. Install forms to allow continuous progress of work and so that forms can remain in place at least 24 hours after concrete placement. B. Check completed formwork and screeds for grade and alignment to following tolerances: 1. Top of Forms: Not more than 1/8 inch in 10 feet. 2. Vertical Face on Longitudinal Axis: Not more than 1/4 inch in 10 feet. C. Clean forms after each use and coat with form release agent ensuring separation from concrete without damage. 3.6 JOINTS A. General: Construct contraction, construction and isolation joints true to line with faces perpendicular to surface plane of concrete. Construct transverse joints at right angles to building corners and changes in pavement direction unless indicated otherwise on the Plans. 1. When joining existing paving, place transverse joints to align with previously placed joints, unless indicated otherwise on the Plans. 2. Contractor shall sequence paving operations in logical order based on the plan layout and approved shop drawings. 3. Contractor shall coordinate with Landscape Architect if there are any discrepancies on the Plans or if there are specific questions regarding joint placement. B. Contraction or Control Joints: Provide weakened-plane contraction or control Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 9 of 14 joints off of all building corners, columns, changes in pavement directions and as shown on the Drawings. Construct contraction or control joints for a depth equal to at least 1/3 of the concrete thickness, as follows: 1. Sawed Joints: Sawcut contraction joints shall be as indicated on the Plans with power saws equipped with shatterproof abrasive or diamond- rimmed blades. Cut 1/8-inch-wide joints into hardened concrete when cutting action will not tear, abrade, or otherwise damage surface and before development of random contraction cracks. 2. Formed or Tooled Joints: Formed contraction joints shall be as indicated on the Plans and with a grooving tool before concrete sets. 3. Joints perpendicular to walls may be less than required depth within 6 inches of the wall, and may stop 2 inches from the wall. 4. If a wet saw is used, all surrounding surfaces need to be washed to remove all slurry and fines caused by the wet saw. C. Construction Joints: Set construction joints at side and end terminations of paving and at locations where paving operations are stopped for more than ½ hour, unless paving terminates at isolation joints. Construction joints should be planned so that they coincide with contraction joint spacing to eliminate extra joints. 1. Construction Joint support: Contractor shall provide sleeved round steel dowels or haunched keyways at construction joints as shown on the Plans. 2. Contractor shall manually insert dowel bars into the construction joints a minimum of 48” on center or two per joint. 3. Continue reinforcement across construction joints unless indicated otherwise. Do not continue reinforcement through sides of strip paving unless indicated. D. Isolation Joints: Form isolation joint material and sealant. 1. Isolation joints shall generally be located where there is a need to isolate flatwork from other paving material, edges of buildings and structures, columns, manholes, footings and changes in material and as specifically shown on the Plans. 2. Extend polyethylene foam joint fillers to full width and depth of joint. 3. Furnish polyethylene foam joint fillers in one-piece lengths. Where more than one length is required, lace or clip polyethylene foam joint filler sections together. 4. Contractor shall manually insert dowel bars into the isolation joints a minimum of 48” on center or two per joint. 5. After concrete is poured, top perforated portion of polyethylene foam joint filler shall be removed. 6. Joint Sealant shall be applied in isolation joint after perforated portion of polyethylene foam joint filler is removed. Sealant color shall match concrete color and Shall Not be Bright White. 3.7 CONCRETE PLACEMENT A. Inspection: Before placing concrete, inspect and complete formwork installation, reinforcing steel, and items to be embedded or cast in. Notify other trades to Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 10 of 14 permit installation of their work. Notify the Architect at least 48 hours prior to each placement. B. Do not place concrete until conduit, catch basin frame and grates, manhole frames and covers, granite curbing and other work to receive the concrete have been inspected and approved by the Architect and all other trades concerned. C. Remove snow, ice, or frost from subbase surface and reinforcing before placing concrete. Do not place concrete on surfaces that are frozen. D. Moisten subbase to provide a uniform dampened condition at the time concrete is placed. Do not place concrete around manholes or other structures until they are at the required finish elevation and alignment. E. Conveying: Concrete shall be handled from the mixer to the place of final deposit as rapidly as practicable by methods that will prevent separation or loss of ingredients and in a manner which will assure that the required quality of the concrete is retained. F. Depositing: Delivery and placement of concrete shall be programmed so that the time lapse between batching and placement shall not exceed 1-1/2 hours. Concrete shall not be allowed a free fall over 4 feet. Concrete shall be deposited as nearly as practicable in its final position to avoid segregation due to rehandling or flowing. G. Concrete shall be deposited continuously, in horizontal layers of such thickness (not deeper than 18 inches) 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. Placing shall be carried out at such a rate that the concrete, which is being integrated, with fresh concrete is still plastic. Concrete which has partially hardened or which has been contaminated with foreign materials shall not be deposited. H. Deposit and spread concrete in a continuous operation between transverse joints. Do not push or drag concrete into place or use vibrators to move concrete into place. 1. When concrete placing is interrupted for more than 1/2 hour, place a construction joint. I. Use a bonding agent at locations where fresh concrete is placed against hardened or partially hardened concrete surfaces. J. Consolidate concrete by mechanical vibrating equipment supplemented by hand-spading, rodding, or tamping. Use equipment and procedures to consolidate concrete complying with ACI 309R. 1. Consolidate concrete along face of forms and adjacent to transverse joints with an internal vibrator. Keep vibrator away from joint assemblies, reinforcement, or side forms. Use only square-faced shovels for hand-spreading and consolidation. Consolidate with care to prevent dislocating reinforcing, dowels, and joint devices. Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 11 of 14 K. Screed paved surfaces with a straightedge and strike off. Use bull floats or darbies to form a smooth surface plane before excess moisture or bleed water appears on the surface. Do not further disturb concrete surfaces prior to beginning finishing operations. 1. Place concrete in two operations; strike off initial pour for entire width of placement and to the required depth below finish surface. Lay welded wire fabric or fabricated bar mats immediately in final position. Place top layer of concrete, strike off, and screed. 2. Remove and replace portions of bottom layer of concrete that have been placed more than 15 minutes without being covered by top layer or use bonding agent if acceptable to Architect. L. When adjoining pavement lanes are placed in separate pours, do not operate equipment on concrete until pavement has attained 85 percent of its 28-day compressive strength. M. Cold-Weather Placement: Comply with provisions of ACI 306R and as follows. Protect concrete work from physical damage or reduced strength that could be caused by frost, freezing actions, or low temperatures. Note to Contractor that seashell concrete flatwork shall not be done under extreme cold conditions. 1. When air temperature has fallen to or is expected to fall below 40 deg F (4 deg C), uniformly heat water and aggregates before mixing to obtain a concrete mixture temperature of not less than 50 deg F (10 deg C) and not more than 80 deg F (27 deg C) at point of placement. 2. Do not use frozen materials or materials containing ice or snow. 3. Do not use calcium chloride, salt, or other materials containing antifreeze agents or chemical accelerators unless otherwise accepted in mix designs. N. Hot-Weather Placement: Comply with provisions of ACI 305R and as follows when hot weather conditions exist. 1. Cool ingredients before mixing to maintain concrete temperature at time of placement to below 90 deg F (32 deg C). Mixing water may be chilled or chopped ice may be used to control temperature, provided water equivalent of ice is calculated to total amount of mixing water. Using liquid nitrogen to cool concrete is Contractor's option. 2. Cover reinforcing steel with water-soaked burlap if it becomes too hot, so that steel temperature will not exceed the ambient air temperature immediately before embedding in concrete. 3. Fog spray forms, reinforcing steel, and subgrade just before placing concrete. Keep subgrade moisture uniform without standing water, soft spots, or dry areas. 3.8 TABBY SEASHELL PAVEMENT FINISH A. Adjacent planting areas shall be protected prior to seashell exposure. B. In accordance with manufacturer’s recommendations, a set retarder shall be sprayed or brushed over the concrete surface. The rate of the application of the Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 12 of 14 retarder shall be sufficient so that the depth of mortar paste removed, on exposing the shells, shall be no more that 1/8-inch. The surface treated with retarder shall be protected by covering with polyethylene sheeting or paper to prevent drying out. The retarded mortar paste shall be removed within 12 hours after placement. The use of a set retarder may be waived by the Architect, provided assurance is guaranteed that all of the seashell surface finish is uniform in exposure and appearance. C. The exposing of the shells shall be accomplished by simultaneously brushing and hosing of the mortar with water. Care shall be exercised not to overexpose or dislodge the shells. D. After the exposing of shells has been completed, the residue of the work shall be removed and legally disposed of, and any existing surface or facility splattered or stained shall be thoroughly cleaned. 3.9 CONCRETE PROTECTION, CURING AND SEALING A. General: Protect freshly placed concrete from premature drying and excessive cold or hot temperatures. Comply with the recommendations of ACI 306R for cold weather protection and ACI 305R for hot weather protection during curing. B. Evaporation Control: In hot, dry, and windy weather, protect concrete from rapid moisture loss before and during finishing operations with an evaporation- control material. Apply according to manufacturer's instructions after screeding and bull floating, but before floating. C. Begin curing after finishing concrete but not before free water has disappeared from concrete surface. D. Curing Methods: Cure concrete by moisture curing, moisture-retaining-cover curing, curing compound, or a combination of these as follows: 1. Moisture Curing: Keep surfaces continuously moist for not less than 7 days with the following materials: a. Water. b. Continuous water-fog spray. c. Absorptive cover, water saturated, and kept continuously wet. Cover concrete surfaces and edges with a 12-inch lap over adjacent absorptive covers. 2. Moisture-Retaining-Cover Curing: Cover concrete surfaces with moisture-retaining cover for curing concrete, placed in widest practicable width, with sides and ends lapped at least 12 inches, and sealed by waterproof tape or adhesive. Immediately repair any holes or tears during curing period using cover material and waterproof tape. 3. Curing Compound: Apply uniformly in continuous operation by power spray or roller according to manufacturer's directions. Recoat areas subjected to heavy rainfall within 3 hours after initial application. Maintain continuity of coating and repair damage during curing period. E. Sealer: Apply uniformly in 2 coats in continuous operations according to Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 13 of 14 manufacturer’s written instructions. Allow first coat to dry before applying second coat. 1. Begin sealing dry surface no sooner than 14 days after concrete placement. 2. 6 months after initial sealing, the Contractor shall clean and reseal all exposed seashell surfaces according to this specification. 3.10 FIELD QUALITY CONTROL TESTING A. Employ a qualified independent testing and inspection agency to sample materials, perform tests, and submit test reports during concrete placement as follows: B. The Owner will employ a qualified testing and inspection agency to sample materials, perform tests, and submit test reports during concrete placement. Sampling and testing for quality control may include the following: 1. Sampling Fresh Concrete: ASTM C 172, except modified for slump to comply with ASTM C 94. a. Slump: ASTM C 143; one test at point of placement for each compressive- strength test but no less than one test for each day's pour of each type of concrete. Additional tests will be required when concrete consistency changes. b. Air Content: ASTM C 231, pressure method; one test for each compressive- strength test but no less than one test for each day's pour of each type of air-entrained concrete. c. Concrete Temperature: ASTM C 1064; one test hourly when air temperature is 40 deg F (4 deg C) and below and when 80 deg F (27 deg C) and above, and one test for each set of compressive- strength specimens. d. Compression Test Specimens: ASTM C 31; one set of four standard cylinders for each compressive-strength test, unless directed otherwise. Mold and store cylinders for laboratory-cured test specimens except when field-cured test specimens are required. e. Compressive-Strength Tests: ASTM C 39; one set for each day's pour of each concrete class exceeding 5 cu. yd. but less than 25 cu. yd., plus one set for each additional 50 cu. yd. Test one specimen at 7 days, test two specimens at 28 days, and retain one specimen in reserve for later testing if required. 2. When frequency of testing will provide fewer than five strength tests for a given class of concrete, conduct testing from at least five randomly selected batches or from each batch if fewer than five are used. 3. When total quantity of a given class of concrete is less than 50 cu. yd., Architect may waive strength testing if adequate evidence of satisfactory strength is provided. 4. When strength of field-cured cylinders is less than 85 percent of companion laboratory-cured cylinders, evaluate current operations and provide corrective procedures for protecting and curing the in-place concrete. 5. Strength level of concrete will be considered satisfactory if averages of Dennis Yarmouth Intermediate Middle School January 19, 2021 Dennis Yarmouth Regional School District 100% Construction Documents Perkins Eastman DPC, project #71011 32 13 14 SEASHELL CONCRETE PAVING 14 of 14 sets of three consecutive strength test results equal or exceed specified compressive strength and no individual strength test result falls below specified compressive strength by more than 500 psi. C. Test results will be reported in writing to Architect, concrete manufacturer, and Contractor within 24 hours of testing. Reports of compressive strength tests shall contain the Project identification name and number, date of concrete placement, name of concrete testing agency, concrete type and class, location of concrete batch in paving, design compressive strength at 28 days, concrete mix proportions and materials, compressive breaking strength, and type of break for both 7-day and 28-day tests. D. Nondestructive Testing: Impact hammer, sonoscope, or other nondestructive device may be permitted but shall not be used as the sole basis for acceptance or rejection. E. Additional Tests: The testing agency will make additional tests of the concrete when test results indicate slump, air entrainment, concrete strengths, or other requirements have not been met. Testing agency may conduct tests to determine adequacy of concrete by cored cylinders complying with ASTM C 42. 3.11 REPAIRS AND PROTECTION A. Remove and replace concrete paving that is broken, damaged, or defective, or does not meet the requirements of this Section. Concrete workmanship that has crumbled and broken edges will not be accepted. B. Drill test cores where directed by Architect when necessary to determine magnitude of cracks or defective areas. Fill drilled core holes in satisfactory pavement areas with Portland Cement Concrete bonded to paving with epoxy adhesive. C. Protect concrete from damage. Exclude traffic from paving for at least 14 days after placement. When construction traffic is permitted, maintain paving as clean as possible by removing surface stains and spillage of materials as they occur. D. Maintain concrete paving free of stains, discoloration, dirt, and other foreign material. Sweep concrete paving not more than 2 days prior to date scheduled for Substantial Completion inspections. E. Refer to 3.9, E herein for resealing operations. END OF SECTION 32 13 14