Dynamic Cone Penetrometer: Low-Tech Tool to Solve an Age-Old Problem

One of the SHRP 2 goals is to produce “tools and techniques that can be used throughout the lifecycle of … pavements” and the expected product is “guide and tool for constructing long-life pavements.” In the past few decades, researchers as well as the highway agencies, have a mind set that only “high-tech” topic is worthwhile to study. Yet high-tech is no guarantee for more reliable results. Dynamic Cone Penetrometer (DCP) is a low-tech device that can be used to evaluate in-site construction quality of subgrade and aggregate base. Density test is merely a method to control construction quality, not a soil strength testing. Not having a soil foundation with acceptable stiffness is the most expensive and troublesome situation for pavement maintenance engineers. DCP is able to record yielding (a reverse of stiffness) profile of pavement foundation. Field test results indicated that a reasonable construction quality specification can be developed. Using this low cost and easy to use device to collect more field samples will assure that an acceptable, in all three dimensions, paving foundation is in place before laying down pavement structure.