3D Analysis and Modelling of Thermal Stress Restrained Specimen Test (TSRST) on Asphalt Mixes with RAP and Roofing Shingles

• The TSRST test setup was improved to measure radial strain variation during the test.
• The repeatability of the TSRST is very good before the failure and reasonable for stress at failure.
• The DBN and 3D-2S2P1D were used successfully to simulate the TSRST test in 3D mode.
• The thermal cracking resistance remains good for mixes with up to 5% shingles and 15% RAP.
• The calibration of the DBN model with 19 calibration parameters gave very good simulation of experimental data.

The thermo-mechanical behavior of asphalt mixes, with Recycled Asphalt Pavement (RAP) and manufacturing waste roofing asphalt shingles (RAS), is investigated. The cracking behavior at low temperature is studied using the Thermal Stress Restrained Specimen Test (TSRST). The experimental device has been improved with a radial strains measurement system during the performed TSRST. Tri-dimensional behavior could thus be investigated. Studied mixes are made with different RAP contents (up to 25%) and RAS contents (up to 10%). First, the influence of the content of RAP and RAS is analyzed and a ranking of the different mixes is proposed based on the classical TSRST results (stress and temperature at failure). Then, in order to simulate TSRST, a three dimensional modelling is performed with the visco-elasto-plastic DBN model. The calibration steps in the small domain (linear visco-elasticity) and in the large strain domain (non-linearity and visco-plastic flow) are presented. The comparison between experimental and simulated results obtained using the DBN model has shown the potential of the DBN model to simulate the low temperature cracking behavior of asphalt mixes.