Identification of the rutting performance on modified asphalt mixtures by a laboratory investigation approach

Asphalt concrete is used as the surface layer for roads and airport pavement. Road pavement has experienced a more rapid deterioration due to increasing traffic loads and changing environmental circumstances. Road damage often occurs due to heavy traffic loads that damage the rutting performance of asphalt mixtures. Some researchers have added additives to improve the performance of asphalt concrete. The utilization additives can improve the performance of asphalt mixtures with the aim to increase the strength of the road pavement structure. In this study, laboratory investigations studied Crumb Rubber Powder (CRP) and Buton Asphalt Natural Rubber (BNA-R) additives to asphalt mixtures. The laboratory analyses used a series of tests: Marshall Standard, Marshall immersion and Wheel Tracking Machine (WTM). Both material additives were added at 5%, 10%, 15%, 20%, or 25% to Asphalt Concrete Wearing Course (AC-WC) with bitumen pen 60/70. Both additive materials showed an increase in the value of the Marshall stability and Marshall immersion compared to the virgin asphalt mixture. However, this condition does not occur with the WTM test results; the addition of 10% CRP had the deepest rutting compared to asphalt mixture without additive. The addition of 10% BNA-R was better able to support the wheel load, resulting is decreased rut depth. The results indicated the ability to predict the asphalt mixture rut depth using WTM. The number of cycles of the WTM test determines the level of the accuracy of the prediction of asphalt mixtures resistance to the pressure of the wheels of the vehicle. The limited ability of WTM is often an obstacle, which can be overcome using an empirical model of the behavior of the rut depth, as presented in this paper.