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ACI 522.1-20 Specifcations for Concrete Construction. 3.2—Subbase 3.2.1 Use only when specified in Contract Documents, Where used, prepare subbase in accordance with Contract Documents. 3.3—Setting formwork 3.3.1 Set, align, and brace forms so that the hardened pavement meets the tolerances specified in 3.9. 3.3.2 Apply form release agent to the form face, which will be in contact with concrete, immediately before placing concrete. 3.3.3 The vertical face of previously placed concrete may be used as a form. 3.3.3.1 Protect previousIy placed pavement from damage. 3.3.3.2 Do not apply form release agent to previously placed concrete. 3.3.4 Placement width shall be as specified in Contract Documents. Concrete placement width shall not exceed 20 ft (6 in) unless otherwise specified. 3.4—Batching, mixing, and delivery 3.4.1 Batch and mix in compliance with ASTM C4/C94M except that discharge shall be completed within 60 minutes of the introduction of mixture water to the cement. Increase time to 90 minutes when using an extended set control admixture. Water addition is permitted at the point of discharge. 3.5—Placing and finishing fixed-form pavement 3.5.1 Deposit concrete either directly from the transporting equipment or by conveyor onto the prewetted subgrade or subbase, unless otherwise specified. 3.5.2 Do not place concrete on frozen suhgrade or subbase. 3.5.3 Deposit concrete between the forms to an approxi. mately uniform height. 3.5.4 Spread the concrete using a come-along, short- handle, square-ended shovel, or rake. 3.5.5 Do not allow foot traffic on the fresh concrete. 3.5.6 Strike off concrete between forms using a form- riding paving machine or vibrating screed. Other strike-off devices may be used when accepted. 3.5.7 Do not use steel trowels or power linishing equipment. 3.5.8 Finish the pavement to the elevations and thickness specified in Contract Documents and meet the requirements of 3.9. 3.6—Placing and finishing slipform pavement 3.6.1 Slipform equipment is permitted. 3.6.2 Deposit and finish concrete in accordance with 3.5, except 3.5.4 and 15,6. 3.12.2.4 Joints shall intersect pavement free edges at 90-degree angles and shall extend straight for a minimum of 1-1/2 ft (0.5 m) from the pavement edge where possible. 3.12.2.5 Align joints of adjacent pavement panels. 3.12.2.6 Align joints in attached or adjacent curbs within 1/4 in. (6 mm) of joints in pavement. 3.12.2.7 Contraction joint depth shall be 1/4 to 1/3 of the pavement thickness. Minimum joint width for saw-cutting is 1/8 in. (3 mm). When using an early-entry dry-cut saw, the depth of...

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