Crack-Healing Investigation in Bituminous Materials

Abstract

Self-healing is one of the great potential processes for service-life extension of asphalt pavements. However, the underlying mechanism is not explained, and a proper way to measure it is not mentioned. It is necessary to understand the self-healing mechanism and to develop a setup to measure it. In this paper, the self-healing process was hypothesized as the reverse process of cracking. Three new test methods were developed to mimic the self-healing process of cracks in bituminous materials (including bitumen, mastics, and asphalt mixtures) in the laboratory. The results indicate that the proposed crack self-healing assessment methods are capable of ranking the self-healing capability of bituminous materials. The crack self-healing process contains two important phases, namely, crack closure and strength gain. The occurrence of these phases is dependent on healing time and temperature.