Research is needed to determine the effect of in-place air voids (i.e., density expressed as a percent of maximum theoretical density) on the performance of asphalt pavements through an analysis of field data from the Long-Term Pavement Performance (LTPP) program and other sources. The best evidence of the impact of in-place air voids on pavement performance comes from laboratory studies. The challenge will be to isolate the effect of in-place air voids from the other factors that can affect pavement performance. Interest in this subject is due to the perceived significance of in-place air voids on pavement performance, and to the fact that any cost associated with increased density during construction is much less than that of the maintenance, preservation, and rehabilitation needed to address reduced pavement life.
The objective of this research was to determine the effect of in-place air voids on the performance of asphalt pavements using data from the LTPP program and other appropriate sources.
The contractor's final report will be posted here as NCHRP Web-Only Document 299 by the summer of 2021.