Test concrete and keep records ofjob-mixed concrete similar to those required for ready-mixed concrete delivery tickets.
Place concrete in accordance with ACl304 and ACI 301. Do not place concrete which does not meet the requirements of these specifications.
Handle concrete in continuous manner as rapidly as possible to final position. Do not covey by vibrator. Where placement consists of several layers, place each layer while preceding layer is still plastic. When free drop is more than 5 feet use tremies.
Pumps may be used only if they can pump the design mix. Do not add fine aggregate or water to mix to satisfy the needs of a pumping device without proper submittal.
Consolidate concrete in accordance with the provisions of ACI 309.
SLABS AND WALKS
Vapor Barrier: Install vapor barrier below interior slabs where required on Drawings, and as shown in details. Lap joints 6" minimmn. Repair or replace areas damaged before concrete is placed.
Compact and Screed: Compact and Screed concrete to grade and float a straight edge to bring surface to required finish level. ConfilID and set all grades and elevations prior to commencing concrete placement. Set all floor drains, sinks, etc., so concrete slopes positively to drain at rate of 118 inch per foot unless otherwise shown on Drawings. Slope exte110r concrete surfaces to drain away from stmcture at rate of 118 inch per foot unless otherwise shown on Drawings. Depress slabs at areas to receive mortar set or ceramic masonry materials.
Finishes: After concrete is sufficiently hardened to bear a person's weight without deep imprint, wood float the surface to a lightly textured, tme, even plane, tme to within 118 inch in 10 feet. Except where special concrete finishes are called for on Drawings, finish surfaces as follows:
Exposed exterior surfaces: After floating surface do not trowel or finish
Tool all edges to smooth radius.
Tool smooth continuous
wide by Yz inch deep control joints to pattern shown on Drawings or as directed by Architect. Exposed interior surfaces: After the surface moisture has disappeared, finish surfaces to a tme, even plane, free from blemishes. Steel trowel to smooth, even, dense finish. In wet areas, provide lightly broomed or burlap belted finish after troweling. At junction of slab with wall, recess expansion joint material % inch, tool slab edge to smooth radius and fill
recess with specified sealant. Treat concrete with a hardener equal Burke Acrylic Cure-Seal unless special concrete hardener is called the Drawings. Interior surfaces to receive subsequent finish:
Smooth "open trowel" finish.
5 Section 03310