Alternative Methods of Flexible Base Compaction Acceptance (0-6587-2)

This report presents the results from the second year of research work investigating issues with flexible base acceptance testing within the Texas Department of Transportation. This second year of work focused on shadow testing non-density-based acceptance methods in parallel with the nuclear density gauge. The research team investigated methods of setting target values and then performed parallel testing of the new devices with the density gauge on three construction projects. In addition to using the nuclear density gauge as the default test device, the research team employed a portable falling weight deflectometer, dynamic cone penetrometer (DCP), and portable seismic pavement analyzer. The field testing showed the DCP to be the most preferred device to use in lieu of the nuclear density gauge. Based on the findings, this report presents a modified construction specification for flexible base and a draft test procedure for using the DCP for compaction acceptance.