Analysis on response behavior of asphalt pavement structure in wide temperature range

Abstract:

To study the actual response behavior of asphalt pavement structure in a wide temperature range, a semi-rigid base asphalt pavement and a full-thickness asphalt pavement were selected as research objects and Falling Weight Deflectometer (FWD) as test load based on the RIOHTrack full-scale test track, and the service temperature and structure response of the two kinds of pavement structures were observed synchronously in the year of 2017. The basic rule of asphalt pavement structure response in wide temperature range was obtained, the relationship models between temperature and deflection, temperature and strain, and temperature and stress were established, and the distribution characteristics of strain and stress along the depth direction of the structures were analyzed. Results show that temperature had significant effect on deflection, strain, and stress response. With seasonal variation, the response values of the asphalt pavement structures in wide temperature range changed alternately with annual cycle, and the values were small in winter and large in summer. Exponential function model can be used to describe the correlation between temperature and structural response parameters, and the decision coefficient R² could reach more than 0.95 with good correlation. Within the wide temperature range, in addition to the monotonous increase or decrease of the strain or stress values inside the structure, temperature variation could also change the strain direction. In pavement structure calculation, it is suggested to select temperature at the most unfavorable season to check the stress state of the asphalt concrete layer in order to ensure the safety of the structure.