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ROOFING REPLACEMENT, RECOVER AND REPAIR PROJECT PAGE 4 <br />INDIAN RIVER COUNTY — JAIL COMPLEX SECTION 035216 <br />JANUARY 4, 2018 LIGHTWEIGHT CONCRETE <br />2.4 DESIGN MIXTURES <br />A. Prepare design mixtures for each type and strength of lightweight insulating concrete <br />by laboratory trial batch method or by field-test data method. For trial batch method, <br />.use a qualified independent testing agency for preparing and reporting proposed <br />mixture designs. <br />1. Limit use of fly ash to not exceed 25 percent of portland cement by weight. <br />B. Limit water-soluble chloride ions to the maximum percentage by weight of cement -or <br />cementitious material permitted by ACI 301 (ACI 301 M). <br />PART 3 - EXECUTION <br />3.1 PREPARATION <br />A: Control Joints: Install control joints at perimeter of roof deck and at junctures with <br />vertical surfaces, including curbs, walls, and vents, for full depth of lightweight <br />insulating concrete. Fill control joints with joint filler. <br />1. Provide 1 -inch- (25 -mm-) wide control joints for roof dimensions up to 100 feet' <br />(30 m) in length; 1-1/2-inch7 (38 -mm-) wide control joints for roof dimensions <br />exceeding 100 feet (30 m). <br />B. Wire Mesh: Place steel wire mesh with longest dimension perpendicular to steel deck <br />ribs. Cut mesh to fit around roof openings and projections. Terminate mesh at control <br />joint's. Lap sides and ends of mesh at least 6 inches (150 mm). <br />C. Welded Wire Reinforcement: Place steel welded <br />dimension perpendicular to steel deck ' ribs. Cut <br />openings and projections. Terminate reinforcement <br />ends of reinforcement at least 6 inches (150 mm). <br />3.2 MIXING AND PLACING <br />wire reinforcement with longest <br />reinforcement to fit around roof <br />at control joints. Lap sides and <br />A. Mix and place lightweight insulating concrete according to manufacturer's written <br />instructions, using equipment and procedures to avoid segregation of mixture and loss <br />of air content. <br />B. Install insulation board according to lightweight insulating concrete manufacturer's <br />written instructions., Place insulation board in wet, lightweight insulating concrete slurry <br />poured a minimum of 1/8 inch (3 mm) over the structural substrate. Ensure full contact <br />of insulation board with slurry. Stagger joints and tightly butt insulation boards. Allow <br />slurry coat to set prior to placing remaining thickness of lightweight insulating concrete. <br />1. Install insulation board in a stair -step configuration with a maximum step-down of <br />1 inch (25 mm). <br />