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D. Placing Concrete in Forms: Deposit concrete in forms in horizontal layers no deeper than <br /> 24 inches and in a manner to avoid inclined construction joints. Where placement consists of several layers, <br /> place each layer while preceding layer is still plastic to avoid cold joints. <br /> 1. Consolidate placed concrete by mechanical vibrating equipment supplemented by hand- <br /> spading,rodding,or tamping. Use equipment and procedures for consolidation of concrete <br /> complying with ACI 309. <br /> E. Placing Concrete Slabs: Deposit and consolidate concrete slabs in a continuous operation, <br /> within limits of construction joints,until completing placement of a panel or section. <br /> 1. Consolidate concrete during placement operations so that concrete is thoroughly worked <br /> around reinforcement,other embedded items and into comers. <br /> 2. Bring slab surfaces to correct level with a straightedge and strike off. Use bull floats or <br /> darbies to smooth surface free of humps or hollows. Do not disturb slab surfaces prior to <br /> beginning finishing operations. <br /> 3. Maintain reinforcing in proper position on chairs during concrete placement. <br /> F. Hot-Weather Placement: When hot weather conditions e�cist that would impair quality and <br /> strength of concrete,place concrete complying with ACI 305 and as specified. <br /> 1. Cool ingredients before mucing to maintain concrete temperature at time of placement to <br /> below 90 deg F(32 deg C). Mi�cing water may be chilled or chopped ice may be used to <br /> ` control temperature,provided water equivalent of ice is calculated to total amount of mixing <br /> 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 in <br /> concrete. <br /> 3. Fog spray forms,reinforcing steel,and subgrade just before placing concrete. Keep subgrade <br /> moisture uniform without puddles or dry areas. <br /> 4. Use water-reducing retarding admixture when required by high temperatures,low humidity, <br /> or other adverse placing conditions,as acceptable to Architect. <br /> 3.7 FINISHING FORMED SURFACES <br /> A. Rough-Formed Finish: Provide a rough-formed fmish on formed concrete surfaces not <br /> exposed to view in the finished Work or concealed by other construction. This is the concrete surface having <br /> texture imparted by form-facing material used,with tie holes and defective areas repaired and patched,and <br /> fms and other projections exceeding 1/4 inch in height rubbed down or chipped oi� <br /> B. Smooth-Formed Finish: Provide a smooth-formed finish on formed concrete surfaces <br /> exposed to view or to be covered with a coating material applied directly to.concrete,or a covering material <br /> applied directly to concrete,such as waterproofing,dampproofing,veneer plaster,painting,or another similaz <br /> system. This is an as-cast concrete surface obtained with selected form-facing material,arranged in an orderly <br /> and symmetrical manner with a minimum of seams or as shown. Repair and patch defective areas with fins <br /> and other projections completely removed and smoothed. <br /> 3.8 MONOLITHIC SLAB FINISHES <br /> A. Float Finish: Apply float finish to monolithic slab surfaces to receive trowel finish and <br /> other fmishes as specified; slab surfaces to be covered with rnembrane or elastic waterproofing,membrane <br /> or elastic roofing,or sand-bed temazzo;and where indicated. <br /> 1. After screeding,consolidating,and leveling concrete slabs,do not work surface until ready <br /> for floating. Begin floating,using float blades or float shces only,when surface water has <br /> Page 5 of 8 <br />