Dynamic Cone Penetrometer in Quality Control of Compaction, State-of-the-Art Report

This paper discusses the applications of DCP in the quality control of compaction of fill in several areas including select backfill, granular base layer, and backfill around utilities. Historically, the compaction levels of pavement subgrade and base layers have been determined by means of in-place density testing. Some testing has been recently performed on cohesive and select backfill material to determine whether there is a reasonable correlation between the DCPI and in-place compaction density. Most reported results of DCP testing have indicated that due to the high variability in DCP results, a correlation could not be applied. The DCP can, however, be effectively used in quality control of granular base layer compaction as well as during backfill compaction of pavement drain trenches. In addition, recent studies indicate that DCP blow count profiles provide a reasonable basis for comparison between compaction equipment, compaction levels, and materials for backfill and embedment materials in the installation of all underground utility structures, including the thermoplastic pipe used in gravity flow applications. A synthesis of current practices and results, and areas of possible future trends are presented.