Revising Thermal Stresses in the TSRST for Low-Temperature Cracking Prediction

Abstract

Two methods are proposed to correct stresses measured with the thermal stress restrained specimen test (TSRST) due to specimen bending. The first method estimates the bending stress from the angle of rotation of the specimen by assuming the location of the axis of rotation in the center of the specimen and perpendicular to the line that connects the two displacement transducers of the TSRST system. Maximum stresses as function of temperature are calculated by superimposing the uniform axial stress and the linear bending stress produced by the eccentricity of the load. The second method calculates the angle of rotation of the specimen more accurately using the data from three measures of displacement. The first method is used to revise thermal stresses of 26 asphalt mixtures prepared in the laboratory and 5 field specimens. The correlation between field and laboratory performance was improved after using the proposed method to correct thermal stresses. Low-transverse cracking was observed for sections with high TSRST strength. Careful analysis of the experimental data obtained from TSRST can provide a good indication of the low-temperature performance of asphalt pavements.