Performance of Asphalt Rubber Mixture Overlays to Mitigate Reflective Cracking

Abstract

Adequately predicting overlay behaviour is essential for flexible pavement rehabilitation to reach the predicted lifespan. Reflective cracking is one of the main failure mechanisms affecting overlay performance. This failure may occur due to cracks in the lower layers that propagate to the overlay due to traffic loads, temperature variations, shrinkage cracking of cement-treated layers, and subgrade movements. This work aims to assess the reflective cracking phenomenon of asphalt rubber mixtures as an overlay through laboratory tests and numerical simulation. Four-point bending equipment and the reflective crack device were used to perform the laboratory tests. A numerical simulation through the finite element method was accomplished to estimate the von Mises strain and develop reflective cracking fatigue laws. The results showed that the asphalt rubber mixtures are suitable for extending overlay lifespan considering reflective cracking. The evaluated asphalt rubber mixtures presented reflective cracking resistance almost eight times greater than the conventional ones.

Comprehensive Laboratory Evaluation of Crack Resistance for an Asphalt Rubber Stress-Absorbing Membrane Interlayer (AR-SAMI)

“…Among them, finite element (FE) and discrete element method (DEM) were most commonly used. For example, Thives et al [23] used Ansys calculations to show that pavement fatigue life could be improved up to eight times using AR-SAMI compared to a regular asphalt mixture under Brazilian climatic conditions. Zeng et al [12] used FE to verify that AR-SAMI with fibers could significantly reduce the stress concentration in cracks.…”