Effect of aging and moisture damage on the cracking resistance of rubberized asphalt mixture

Abstract

The use of crumb rubber to modify asphalt mixtures has astounding economic and environmental benefits. However, the use of asphalt mixture modified by crumb rubber is uncertain specifically when it is added by the dry method due to the low stability and cracking performance of the produced mixtures. Moreover, the high air void content of the produced mixture results in its low resistance to moisture damage and aging effect. This study attempts to investigate the effect of moisture damage and aging on the cracking performance of rubberized asphalt mixtures. Indirect tensile strength test was used to investigate the CT index, fracture energy, and tensile strength. The IDEAL-CT characterization correlated well with field performance in terms of thermal cracking and reflective cracking. The test was conducted before and after exposure of the asphalt samples to two levels of aging and one level of moisture damage. Results show that the total fracture energy of rubberized asphalt is higher than that of the control mixtures. However, the rubberized mixture shows low tensile strength particularly for the moisture conditioning. Meanwhile, the rubberized mixture has a higher CT index value than the control mixtures.