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40-27 BUILDING <br />CAST -IN -PLACE CONCRETE 1 <br />BRPH ARCHITECTS -ENGINEERS, INC. <br />C. Contraction Joints in Slabs -on -Grade: Form weakened -plane contraction joints, <br />sectioning concrete into areas as indicated. The soff-cut saw should be used to a <br />depth of 1 '/2" and a conventional saw usage requires a depth of/4" slab thickness. For <br />slabs with thickness greater that 8" consult with saw manufacturer for recommended <br />depth. <br />1. Sawed Joints: Form contraction joints with power saws equipped with <br />shatterproof abrasive or diamond -rimmed blades. Cut 1/8-inch-wide joints into <br />concrete when cutting action will not tear, abrade, or otherwise damage surface <br />and before concrete develops random contraction cracks. <br />2. Install plate dowels and armored edges at designated contraction joints as per <br />manufacturer's installation instructions. <br />D. Isolation Joints in Slabs -on -Grade: After removing formwork, install joint -filler strips at <br />slab junctions with vertical surfaces, such as column pedestals, foundation walls, grade <br />beams, and other locations, as indicated. <br />Terminate full -width joint -filler strips not less than 1/2 inch or more than 1 inch <br />below finished concrete surface where joint sealants, specified in Division 07 <br />Section "Joint Sealants," are indicated. <br />3.7 CONCRETE PLACEMENT <br />A. Before placing concrete, verify that installation of formwork, reinforcement, and <br />embedded items is complete and that required inspections have been performed. <br />B. Do not add water to concrete during delivery, at Project site, or during placement <br />unless approved by Engineer. <br />C. Before test sampling and placing concrete, water may be added at Project site, subject <br />to limitations of ACI 301. <br />1. Do not add water to concrete after adding high -range water -reducing admixtures <br />to mixture. <br />2. Redosage with the high range water reducing admixture onsite can be done to <br />restore the agreed upon placing slump. Slump loss will occur at the target slump <br />because of delays in concrete placement and/or high temperatures. The testing <br />laboratory should prepare a chart indicating dosage required for the concrete <br />remaining to be placed and an expected slump increase. <br />D. Deposit concrete continuously in one layer or in horizontal layers of such thickness that <br />no new concrete will be placed on concrete that has hardened enough to cause seams <br />or planes of weakness. Deposit concrete to avoid segregation. <br />1. Deposit concrete in horizontal layers of depth to not exceed formwork design <br />pressures and in a manner to avoid inclined construction joints. <br />2. Consolidate placed concrete with mechanical vibrating equipment according to <br />ACI 301. <br />C06922.001.00 03 30 04 - 12 <br />05-22-14 ' <br />