Elastic Wave Measurement System Using FWD for Asphalt Pavement

Abstract

This paper describes stiffness estimation methods for the base layer of asphalt pavement using quasi-static back-calculation, dynamic back-calculation and transit elastic wave measurement system. These techniques are based on FWD devices: FWD (50kN load capacity), a portable type of FWD (15 kN load capacity) and a new type of portable of FWD (25 kN load capacity). The surface acceleration is measured by outer accelerometer of FWD devices. The system consists of a portable PC, a sampling AID card, an acceleration system, FWD or a portable FWD and MATLAB-based software. It revealed that the stiffness of base layer was less influenced by dynamic back-calculation or transit elastic wave measurement system. It was confirmed that the transit elastic wave measurement can be used to evaluate the stiffness characterizing the mechanical response of the pavement at each tested site.