An Experimental Investigation into the Effect of Ceramic Fiber on the Fatigue Cracking of Stone Matrix Asphalt

Abstract

Fatigue cracking of the asphalt mixture is a process whereby micro-cracks in the asphalt–aggregate interface propagates into extensive coordinated cracks under repeated loads. This process is the main cause of failure in flexible pavement and reduces its serviceability. Fiber reinforcement has received significant attention in the last two decades for finding viable solutions to increase the fatigue resistance of stone matrix asphalt (SMA). Accordingly, ceramic fiber (CF) as an asphalt binder modifier was used in this study to evaluate the fatigue behavior using mechanical and rheological tests. For this purpose, asphalt binder samples with different percentages of CF were subjected to short term and long-term aging according to the rolling thin film oven (RTFO) and pressure aging vessel (PAV), and dynamic shear rheometer (DSR) test was performed at mid temperature. Also, the fatigue life test was performed by indirect tensile fatigue test at two temperatures and five stress levels on asphalt mix samples made with controlled and modified asphalt binders. Based on the results, it is observed that asphalt binder modified with CF have higher and lower complex shear modulus and phase angle, respectively, compared to control asphalt binder. Also, the results of fatigue test show that using CF up to 5% increases fatigue life of mixtures. In addition, with enhancing temperature and stress level, fatigue life decreased in all samples, with a lower rate in CF modified samples.