Permeability of hot mix asphalt concrete as affected by binder content.

摘要

One of the primary objectives when constructing hot mix asphalt concrete (HMAC) is achieving the target density in order for the pavement to be impermeable. If the density is too low, water infiltration causes pavement damage from freeze-thaw and other effects caused by the presence of water. If the pavement density is too high, rutting, flushing, and shoving will occur.;This research used the Florida Method of Test for Measurement of Water Permeability of Compacted Asphalt Paving Mixtures to examine how permeability is affected by binder content and compaction level. Asphalt samples containing 5.2, 5.7, 6.2, and 6.7 percent binder at air void levels of 4, 6, 8, and 10 percent were tested in a Florida Department of Transportation (FDOT) style permeameter. Gyratory and indirect tension (IDT) strength test data were also used to evaluate the effect binder has on compaction and rutting resistance.;This research suggests several changes to West Virginia's construction specifications, including permeability testing as part of the mix design process. Changing the maximum air void specifications from 8 to 7 percent is suggested to reduce the possibility of the construction of permeable pavements to reach the threshold where permeability drastically increases. Recommendations are also made for further research.