Measurement and evaluation on deterioration of asphalt pavements by geophones

Abstract To determine a feasible strategy for maintenance and rehabilitation of in-service asphalt pavements, the precise in-situ determination of pavement deterioration is of significant importance. Conventional methods such as fatigue tests on core specimens in the laboratory or stationary deflection measurements in-situ exhibit their own disadvantages. This study proposes an innovative system to measure and evaluate the deterioration of asphalt pavements under moving loads by means of geophones, a mobile load simulator (MLS) and a back-calculation tool. A test track was evaluated with this method at three different service states. For each state, the vibrations of the test track induced by a passing truck were measured by an array of geophones. The vibrations were transferred to a surface deflection in the analysis and then used to compute the material parameters of the test track with the back-calculation tool. The results show that the deflections derived from an individual geophone are in high agreement with each other and thus the repeatability indicates the measurement is mechanically robust. The computational variation of material parameters and the corresponding mechanical responses are consistent with the increase of loading cycles applied by the MLS. It indicates that the proposed system is able to provide a tool for an accurate and efficient measurement of the surface deflection and evaluation of the deterioration of asphalt pavements under moving loads.