DCP, a Low-Tech Approach to Control Construction Quality

A pavement performs as well as it is constructed, not necessary as it is designed. A good construction quality is the essential factor of good performance. In the past few decades, researchers as well as the highway agencies, have a mind set that "high-tech" is the only approach for modern testing devices development. Yet high-tech is no guarantee for more reliable results. Dynamic Cone Penetrometer (DCP) is an easy to use, low-tech device for evaluation of in-site quality of subgrade and aggregate base. Density test is the most commonly adopted method to monitor subgrade quality. Yet, density test is merely a method to control construction quality, not a soil strength testing. Not having a strong enough soil foundation is the most expensive and troublesome situation for pavement maintenance engineers. DCP is able to record yielding (a reverse of stiffness) profile of a pavement foundation up to a meter in depth. Based on field test results, a reasonable construction quality specification can be developed. Using this low cost and easy to use device to collect more field samples will assure an acceptable paving foundation is in place before laying down pavement structure.