Prediction of Low-temperature Performance of Asphalt based on Four-point Bending Notched Beam Test

Abstract

The mechanism of thermal cracking in asphalt is closely linked to thermal cracks in asphalt pavements. Nevertheless, the majority of prior research on the low-temperature behavior of asphalt failed to comprehensively incorporate the thermal cracking mechanism. This work utilizes the fracture temperature as a criterion for assessing asphalt low-temperature cracking. It uses the four-point bending notched beam test (4P) to forecast the low-temperature behavior of asphalt. This prediction is made by deductive reasoning, taking into account the thermal cracking mechanism. The specific method was as follows: the viscoelastic properties and contraction strain of asphalt were determined through the main curve test and low-temperature contraction test, respectively. These results served as a basis for calculating thermal stress and pseudo cumulative strain energy. Additionally, the thermal stresses of asphalt were obtained by the Boltzmann superposition principle, and the pseudo cumulative strain energy density was calculated by using the line low-temperature contraction obtained from the low-temperature contraction test as the pseudo strain. 4P test was employed to determine the critical strength and critical energy of various asphalt cracking. These values were then utilized as a basis to deduce the fracture temperature of asphalt. The accuracy and reliability of this method for predicting the low-temperature performance of asphalt were confirmed by comparing the measured fracture temperatures of asphalt mixtures with the same gradation to the predicted values. A novel technique was presented for assessing the low-temperature performance of asphalt.