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ST. BARBARA CATHOLIC SCHOOL TASK 2 75-24272-01 <br />DIOCESE OF ORANGE SEPTEMBER 12TH, 2024 <br />SANTA ANA, CA BID & PERMIT SET <br /> <br />CONCRETE PAVING 321313 - 10 <br />B. Moisten subgrade or base to provide a uniform dampened condition at the time concrete is <br />placed. Do not place concrete around manholes or other structures until they are at the <br />required finish elevation and alignment. <br /> <br />C. Comply with requirements and with ACI 304R for measuring, mixing, transporting, and <br />placing concrete. <br /> <br />D. Deposit and spread concrete in a continuous operation between transverse joints. Do not push <br />or drag concrete into place or use vibrators to move concrete into place. <br /> <br />E. Use a bonding agent at locations where fresh concrete is placed against hardened or partially <br />hardened concrete surfaces. <br /> <br />F. Consolidate concrete by mechanical vibrating equipment supplemented by hand-spading, <br />rodding, or tamping. Use equipment and procedures to consolidate concrete complying with <br />ACI 309R. <br /> <br />1. Consolidate concrete along face of forms and adjacent to transverse joints with an <br />internal vibrator. Keep vibrator away from joint assemblies, reinforcement, or side <br />forms. Use only square-faced shovels for hand-spreading and consolidation. <br />Consolidate with care to prevent dislocating reinforcing, dowels, and joint devices. <br /> <br />G. Screed paved surfaces with a straightedge and strike off. Use bull floats or darbies to form a <br />smooth surface plane before excess moisture or bleed water appears on the surface. Do not <br />further disturb concrete surfaces prior to beginning finishing operations. <br /> <br />H. Curbs and Gutters: When automatic machine placement is used for curb and gutter placement, <br />submit revised mix design and laboratory test results that meet or exceed requirements. <br />Produce curbs and gutters to required cross section, lines, grades, finish, and jointing as <br />specified for formed concrete. If results are not acceptable, remove and replace with formed <br />concrete. <br /> <br />I. Cold-Weather Placement: Comply with provisions of ACI 306R and as follows. Protect <br />concrete work from physical damage or reduced strength that could be caused by frost, <br />freezing actions, or low temperatures. <br />1. When air temperature has fallen to or is expected to fall below 40 deg F (4 deg C), <br />uniformly heat water and aggregates before mixing to obtain a concrete mixture <br />temperature of not less than 50 deg F (10 deg C) and not more than 80 deg F (27 deg C) <br />at point of placement. <br />2. Do not use frozen materials or materials containing ice or snow. <br />3. Do not use calcium chloride, salt, or other materials containing antifreeze agents or <br />chemical accelerators unless otherwise accepted in mix designs. <br /> <br />J. Hot-Weather Placement: Place concrete complying with ACI 305R and as specified when hot <br />weather conditions exist. <br />1. Cool ingredients before mixing to maintain concrete temperature at time of placement <br />to below 90 deg F (32 deg C). Mixing water may be chilled or chopped ice may be <br />used to control temperature, provided water equivalent of ice is calculated to total <br />amount of mixing water. Using liquid nitrogen to cool concrete is Contractor's option. <br />2. Cover reinforcing steel with water-soaked burlap if it becomes too hot, so that steel <br />temperature will not exceed the ambient air temperature immediately before embedding <br />in concrete.