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SITE CONCRETE <br />Section 03000 <br />15-1207 <br />thoroughly worked around reinforcement and embedded fixtures and into comers of forms. <br />Vibrating shall not be applied to concrete which has already begun to initially set nor shall it <br />be continued so long as to cause segregation of materials. <br />H. Concrete Paving: <br />1. All concrete paving shall be formed and finished to required line and grades. Concrete <br />paving shall be true and flat with a maximum tolerance of 1/8" in 10'for flatness. <br />Concrete paving which is not flat and are outside of the maximum specified tolerances <br />shall be made level by the Contractor at no additional expense to the Owner. <br />2. Thoroughly water and soak the concrete paving subgrade as required to achieve <br />required moisture content prior to the concrete pour. Provide damming as required to <br />keep water within the formed area and to allow for proper saturation of the subgrade. <br />3. Concrete vibrator shall be used to assist concrete placement. Contractor shall have <br />spare concrete vibrator on site during concrete placement. <br />Placing in hot weather: Comply with ACI 305R-91. Concrete shall not exceed 85 degrees F <br />at time of placement. Concrete shall be delivered, placed and finished in a sufficiently short <br />period of time to avoid surface dry checking. Concrete shall be kept wet continuously after <br />tempering until implementation of curing compound procedure in accordance with this <br />specification. <br />Placing in cold weather: Comply with ACI 306R-02. Protect from frost or freezing. No <br />antifreeze admixtures are permitted. When deposited concrete during freezing or near - <br />freezing weather, mix shall have temperature of at least 50 degrees F but not more than 90 <br />degrees F. Concrete shall be maintained at temperature of at least 50 degrees F for not less <br />than 72 hours after placing or until it has thoroughly hardened. Provide necessary thermal <br />coverings for any flat work exposed to freezing temperatures. <br />K. Horizontal construction joint: Keep exposed concrete face of construction joints continuously <br />moist from time of initial set until placing of concrete; thoroughly clean contact surface by <br />chipping entire surface not earlier than 5 days after initial pour to expose clean hard <br />aggregate solidly embedded, or by approved method that will assure equal bond, such as <br />green cutting. If contact surface becomes contaminated with soil, sawdust or other foreign <br />matter, clean entire surface and re -chip entire surface to assure proper adhesion. <br />3.09 CONCRETE FINISHES <br />A. Concrete Paving Finishing: Finish surface as required by ACI 302.1 R. Use manual screeds, <br />vibrating screeds to place concrete level and smooth. Use "jitterbugs" or other special tools <br />designed for the purpose of forcing the course aggregate below the surface leaving a thick <br />layer of mortar 1 inch in thickness. After tamping the concrete, wood float surface to a true <br />and even plane. After floating with a wood bull float, make 2 passes with a steel Fresno <br />trowel to start sealing the concrete surface. While concrete is still wet but sufficiently <br />hardened to bear a persons weight on knee boards, start troweling with a steel hand trowel or <br />a machine trowel in larger areas. Use sufficient pressure to bring moisture to surface. After <br />surface moisture has disappeared, finish concrete utilizing steel, hand or power trowel. <br />Surface shall be free from trowel marks, depressions, ridges or other blemishes. Tolerance <br />for flatness shall be 1/8" in 10'. Provide final finish as follows: <br />1. Flatwork, medium broom finish: Typical finish to be used at all exterior walks, stairs and <br />10 <br />