Mode I reflection cracking resistance of strengthened asphalt concretes

초록

This study was devised to evaluate the performance of polymer-modified asphalt mixtures and specially designed reinforcement techniques against reflection cracking for the typical asphalt pavement overlays. Selected polymers from previous studies were used as asphalt modifiers along with fibre; a polypropylene film (vinyl) and a grid were used as reinforcing materials. Using the reinforced asphalt mixtures with the optimum asphalt content from mix design, an asphalt mixture slab was made and cut into two specimens. A layer of grid or polypropylene film was placed at the bottom of each specimen to strengthen the pavement layer against cracking. Simulated-repeated loading was applied to the asphalt mixture specimens using a hydraulic dynamic loading frame. The asphalt mixture specimens were bonded to a cement concrete base which was cut to simulate a crack. Crack propagation under repeated loading was monitored and the effectiveness of the devised crack preventing techniques was evaluated. From the test results, a significant retardation of crack progress was monitored from some of the modified and reinforced asphalt mixtures.