SPR 19-573: Non-Nuclear Methods for Compaction Control of Unbound Soil

This Research Program for the period July 1, 2018 to June 30, 2020 is submitted in compliance with the provisions of Section 307 of Title 23, United States Code, and describes programs and operations for planning activities in the Kentucky Transportation Cabinet (KYTC) and the Kentucky Cooperative Transportation Research Program (KCTRP). This program modifies and updates such programs and is specifically intended to reflect the needs of the Kentucky Transportation Cabinet. It is fully expected that products from this program will also have national applications. The University of Kentucky Transportation Center is the main research group for the the Kentucky Transportation Cabinet. The SPR grant is the funding the is supplied each year for the many topics the Center is asked to research for KYTC The KCTRP is concerned with the development and conduct of a comprehensive research program in cooperation with the U.S. Department of Transportation, Federal Highway Administration (FHWA). In addition to research developed in cooperation with FHWA, the KCTRP may perform other services for the KYTC on a nonparticipating basis. The scope of these services could include activities such as research studies and special investigations of various engineering and operation activities. The Research Program and Implementation Advisory Committee (RPIAC), headed by the State Highway Engineer and coordinated through the Research Coordinator, will give direction to the research program. Proper density in the pavement, base, and subgrade layers is a key factor in ensuring a long-lasting road that meets performance expectations. It is very important for transportation agencies and contractors to have reliable devices and methods to determine in-situ density. Kentucky Transportation Cabinet (KYTC) inspectors and engineers use nuclear gauges to perform soil compaction tests to measure soil density and water content. Nuclear gauges are expensive to maintain, require special storage and safety considerations, repeated training, and certification for their use. In the past 20 years, extensive research and development into non-nuclear density gauges (NNDG) has been performed. NNDGs can offer all of the benefits of the NDG while eliminating the need for licenses, hassles, and general costs of NDG ownership. Some NNDGs commonly used by transportation agencies and contractors include dynamic cone penetrometer (DCP), Light Falling Weight Deflectometer (LFWD), or Lght Weight Deflectometer (LWD), Soil Density Gauge (SDG), Electrical Density Gauge (EDG), Moisture Density Indicator (MDI), Pavement Quality Indicator (PQI), and GeoGauge. The focus of this research is to investigate the current state of the practice for the use of non-nuclear test methods for compaction control of unbound soil and granular layers and make recommendations to KYTC on the use of devices for compaction control.