摘要: |
This report is a summary of the results of a compaction study using recycled hot mix asphalt concrete conducted during August 1983 in an indoor facility at CRREL in Hanover, New Hampshire. This study compared three kinds of compactors for optimum performance, and also considered such factors as temperature of the asphalt concrete mix, number of passes, size and depth of patches, and the number of lifts to fill the holes. Results showed that a vibratory roller and vibratory plate compactor could both coapact patches to the desired 98% of laboratory density, but that a 200-lb lawn roller could not. Temperature of the hot recycled mix la critical, with 250°F being the cut-off temperature. It was shown that if the mix is not compacted promptly after placement and is allowed to cool below 250®F, proper compaction may not be attained. Single lifts of 3-ln., 6-ln. and 9-in. depth were compacted to 98X density using the vibratory plate compactor on mix above 250*F in 18-x24-ln. boles. In larger 3-x4-ft holes. 98X density was obtained only with the steel wheel vibratory roller on patches placed in two 3-ln.-thick lifts. The number of coverages of the compactors influences densities obtained. By doubling coverages of the steel wheel vibratory compactor from 6 to 12, the density increased from 96.9Z to 99.OZ. |