Evaluating the Effects of Ground Tire Rubber (GTR) Modified Asphalt and Dry ry Added Treated GTR on the Performance Characteristics of RAP Mixtures

摘要

One approach to reduce the cost of asphalt mixtures and to produce environmentally friendly mixtures is to use more readily available recycled materials like Reclaimed Asphalt Pavements(RAP) and Ground Tire Rubber (GTR).In this study, GTR and Treated GTR were added to binder and to high RAP contentmixtures. Rutting performance of the binders was evaluated by conducting the Multiple StressCreep Recovery test, fatigue performance was evaluated by the Linear Amplitude Sweep test, andthe degree of separation was measured by conducting the Cigar Tube Test . Also, the effect of asuspension agent on the degree of separation was determined. GTR and Treated GTRsignificantly improved the rutting and fatigue performance of the asphalt binders. The suspensionagent successfully decreased the degree of separation between rubber particles and binder.GTR was introduced into the binder and the resulting rubberized binder was used todesign a 9.5 mm Superpave mixture. The Treated GTR was directly added to the mixture. TreatedGTR mixtures were mixed and compacted at lower temperatures compared to GTR mixtures. Thedynamic modulus was determined using the Asphalt Mixture Performance Tester, reflectivecracking performance was evaluated using the Texas Overlay Tester, low temperature crackingresistance was evaluated by the Thermal Stress Restrained Specimen Test, and rutting andmoisture susceptibility was evaluated using the Hamburg Wheel Tracking Device.GTR and Treated GTR made the mixtures slightly more prone to reflective cracking, butimproved their resistance to rutting, moisture susceptibility, and low temperature cracking.