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APRODUCED AT GOVERNMENT EXPENSE <br />3.3.1 Cold Weather: ACI 3068. Provide and maintain 50 degrees F minimum <br />concrete temperature. Do not place concrete when the ambient temperature is <br />below 40 degrees F. Cover concrete and provide with a source of heat <br />sufficient to maintain 50 degrees F minimum while curing. <br />3.3.2 Hot Weather: ACI 3058. Concrete temperature from initial mixing <br />through final cure shall not exceed 90 degrees F. Cool ingredients before <br />mixing, or substitute chip ice for part of required mixing water or use other <br />suitable means to control concrete temperature to prevent rapid drying of <br />newly placed concrete. Shade the fresh concrete and start curing as soon as <br />the surface of the fresh concrete is sufficiently hard to permit curing <br />without damage. <br />3.4 SURFACE FINISHES: ACI 301 for repair and finish, unless otherwise <br />specified. Slope floors uniformly to drains where drains are provided. <br />After troweling is completed, apply a liquid chemical sealer -hardener to <br />interior slabs that do not receive floor covering. <br />3.3.1 Defects: Repair formed surfaces by removing minor honeycombs, pits <br />greater than 1 square inch surface area or 0.25 inch maximum depth, or <br />otherwise defective areas. Provide edges perpendicular to the surface and <br />patch with nonshrink grout. Patch tie holes and defects when the forms are <br />removed. Concrete with extensive honeycomb (including exposed steel <br />reinforcement, cold joints, entrapped debris, separated aggregate, or other <br />defects) which affect the serviceability or structural strength will be <br />rejected, unless correction of defects is approved. Obtain approval of <br />corrective action prior to repair. The surface of the concrete shall not <br />vary more than the allowable tolerances of ACI 301. Exposed surfaces shall <br />be uniform in appearance and finished to a smooth form finish, unless <br />otherwise specified. <br />3.4.2 Floated Finish: Place, consolidate, and immediately strike off <br />concrete to obtain proper contour, grade, and elevation before bleedwater <br />appears. Permit concrete to attain a set sufficient for floating and <br />supporting the weight of the finisher and equipment. If bleedwater is <br />present prior to floating the surface, drag the excess water off or remove by <br />absorption with porous materials. Do not use dry cement to absorb <br />bleedwater. Surface shall be level to within 1/4 inch in 10 feet where floor <br />drains are not provided. <br />3.4.3 Steel Troweled Finish: First, provide a floated finish. When slab <br />has attained a proper set, trowel to a smooth, hard, dense finish. Finished <br />surfaces shall be free of trowel marks, uniform in texture, flat within 0.01 <br />foot (approximately 1/8 inch) in 10 feet. Hand -finish portions of the slab <br />not accessible to power finishing equipment (e. g., edges, corners) to match <br />the reaminder of the slab. Power trowel once and finally hand trowel where a <br />finished floor covering (e. g., tile, carpet) is specified. Power trowel <br />twice and finally hand trowel for exposed concrete floors. <br />al W1 111 = <br />M1191;J11=71M <br />