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bedding of the subgrade shall be compacted to a minimum density of 95 percent of maximum density as determined by AASHTO T- 180. C . Subgrade material shall be composed primarily of granular soils with no more than a moderate amount of silt or clay and shall meet both the following bearing values : Minimum Lime Rock Bearing Ratio (LBR) = 40. - Florida Bearing Value (FBV) = 50. The subgrade shall be compacted and shaped to the plan cross section. Compaction shall be to a minimum density of 98 percent of maximum density as determined by AASHTO T- 180 . The finished surface shall be free of loose material. D. Mortar blocks or plastic chairs specifically designed for such purpose shall be evenly placed on the finished subgrade to adequately support and center the reinforcing steel in the concrete pour. 3 . 02 REINFORCING STEEL A . Lap splices of deformed bars shall be 24 times the nominal bar diameter in the longitudinal direction. Splices of W .W. Fabric shall be a minimum or six (6) inches. B . Deformed bars shall be tied with soft iron wire at the intersection of the longitudinal and lateral bars. 3 .03 MIXING AND PLACING CONCRETE A . Concrete pavement shall be constructed on the prepared subgrade in accordance with these Specifications and in reasonably close conformity with the lines, grades, thickness, and typical cross sections shown on the Plans. The subgrade shall be wet down just prior to placing the concrete to minimize loss of water from the concrete, but there shall be no standing water when the concrete is being placed. B . MIXING CONCRETE Concrete mixed in truck mixers shall be at the speed designated as mixing speed by the manufacturer for a total of 75 - 100 revolutions of the drum unless additional water is added in conformance with paragraph C, below. Time of mixing in a central mix plant shall be a minimum of sixty (60) seconds. C . TRANSPORTING CONCRETE Concrete may be transported any distance providing it is discharged on the subgrade within the required slump range and meets the time requirements of paragraph D, below. If additional water is required to maintain the specified slump of concrete transported in truck mixers, it may be added with the permission of the Engineer' s Representative only. In this case, a minimum of 20 additional revolutions of mixer drum at mixing speed shall be required before discharging of the concrete. D . CONCRETE TIME LIMIT The length of time that the concrete can be held in the truck shall conform to the 02752 — Concrete Paving 02752- 5