Laserfiche WebLink
CONCRETE IMPROVEMENTS 02 5500- <br />3 <br /> <br />b. Proportioning and mixing is in compliance with a design mix which has <br />been field tested in accordance with the herein requirements and <br />produces the required compressive strength under like conditions. <br />c. Statement of type and amount of any admixtures. <br />d. All certificates shall include the Material and Supplier's mix design <br />number. <br />2. At time of delivery provide certified delivery ticket stating volume of concrete <br />delivered and time of mixing, or time of load-out in case of transit mixers. <br />1.04 JOB CONDITIONS <br />A. Admixtures shall not be used except upon the prior written permission of the <br />Engineer and, if permitted, the concrete containing same will be subject to the <br />same compliance testing as herein specified for the various classes of concrete. <br />B. Temperature of mixed concrete, immediately prior to placement, shall not be less <br />than 50 F, nor more than 90F. Aggregates and water shall be heated or cooled <br />at the mixing plant by supplier as necessary to produce concrete within these <br />limits. Neither aggregates nor mixing water shall be heated to exceed 150F. <br />C. No additional mixing water shall be incorporated into the concrete during transport <br />or after arrival at the work site unless such water is specifically authorized by the <br />Engineer. If authorization to add mixing water is obtained and mixing water is <br />added to the mix, the mixer drum shall then be revolved a minimum of thirty (30) <br />revolutions. <br />D. Hand mixing of Portland Cement Concrete shall not be allowed except upon prior <br />written approval. <br />E. Where a portion of existing concrete improvements is to be reconstructed, the <br />section to be removed shall first be a cut with an approved concrete saw to a <br />minimum depth of one-half the depth of the existing concrete at the first score line <br />beyond the area to be replaced. <br />F. Where concrete removal is required, it shall be removed to the nearest score line <br />of joints. <br />G. Prior to placing concrete for concrete structures, Contractor shall first secure <br />approval of the forms and any required reinforcement. <br />PART 2- PRODUCTS <br />2.01 AGGREGATE FOR PORTLAND CEMENT CONCRETE <br />A. Aggregates for Portland Cement Concrete shall conform to the requirements of <br />Section 90-1.01C(2) and 90-1.02C(3) of the State Standard Specification. <br />B. Unless otherwise specified or called for on the plans for the work, aggregate size <br />and gradation for Portland Cement Concrete shall conform to the requirements of <br />Section 90-1.02C(4)(d) of the State Standard Specifications for one inch (1") <br />maximum combined aggregate. <br />2.02 WATER FOR PORTLAND CEMENT CONCRETE <br />A. Water for mixing and curing concrete and for washing aggregates shall conform to <br />the requirements of Section 90-1.02D of the State Standard Specifications. <br />7.A. - Page 22 of 121 <br />28