Effects of Mixture Aging on the Performance of Gap Graded Asphalt Mix Experimented on the Malaysian North-South Expressway
Gap Graded Asphalt (GGA) is a new type of asphalt mix developed by OPUS International. It has been successfully experimented on several trial sites along the Malaysian North South Expressway. GGA differs from ordinary dense asphalt by incorporating a high proportion of coarse aggregate, filler and bitumen. The high coarse aggregate structure helps to build a stable matrix enabling it to better resist permanent deformation. The main objective of this study is to investigate the effects of mixture aging on GGA mix properties and compare the mixture performance with porous asphalt (PA), and asphaltic concrete (AC). The performance tests conducted in this study includes indirect tensile strength (ITS), resilient modulus, abrasion loss, permeability, skid resistance and rutting. A One-Way ANOVA statistical analysis was used to analyze the results. From the results, aging duration has a statistically significant effect on the resilient modulus and skin temperature difference. GGA mixtures exhibit lower ITS and resilient modulus compared to PA and AC. However, GGA mix exhibits better resistance to rutting and being impermeable enables it to completely waterproof the pavement.