INVESTIGATION OF ASPHALT PAVEMENT WITH ADDED CRUMB RUBBER
Waste tires must be recycled in environmentally safe ways that meet civil engineering concerns while fulfilling standards for construction materials. Used tires can be processed into rubber powders with particle sizes of 0–2 mm, a suitable fine aggregate for mixing into road pavements. We tested asphalt mixtures with rubber added using the dry method, comparing their properties with a traditional mixture. We tested asphalt–rubber mixtures with rubber incorporated at either ambient temperature or preheated. Rubberized and traditional asphalt concretes compared well in void content, indirect tensile strength ratio, rut depth, and wheel-track slope. After optimizing the rubber content added, we laid an experimental road course with the asphalt–rubber mixture.
橡胶颗粒沥青混合料性能研究 Study on Capability of Crumb Rubber Asphalt Mixture
为了研究橡胶颗粒沥青混合料的路用性能，通过水稳定性、高温稳定性、低温抗裂性以及抗剥落性方面，对不同粒径、不同掺量的橡胶颗粒沥青混合料进行了对比。试验结果表明：橡胶颗粒的加入对沥青混合料的路用性有明显的改善作用，当掺量在3%时，对沥青混合料的改善效果达到最优。 In order to evaluate durability of rubber particles asphalt mixture, through water stability, high temperature stability, low temperature crack resistance and anti stripping property, the different amount of crumb and different particle sizes of rubber asphalt mixture were compared. Experimen-tal results show that the addition of rubber particles can improve the durability of asphalt mixture remarkably. When the dosage is 3%, the improvement effect of asphalt mixture is optimal.
Development of Criteria for the Use of Asphalt-Rubber as a Stress-Absorbing Membrane Interlayer (SAMI).
Abstract : This report documents over 2 years of research efforts to characterize asphalt-rubber mixtures to be used in Stress-Absorbing Membrane Interlayers (SAMI). The purpose of these SAMIs is to retard or prevent reflection cracking in asphalt-concrete overlays. Several laboratory experiments and one field trial were conducted to define significant test methods and parameters for incorporation into construction design and specification documents. Test methods used in this study included a modified softening point test, force-ductility, and Schweyer viscosity. Variables investigated included (1) Laboratory-mixing temperature; (2) Rubber type; (3) Laboratory storage time; (4) Laboratory storage condition; (5) Laboratory batch replication; (6) Laboratory mixing time; (7) Field mixing time; (8) Laboratory test temperature; (9) Force-Ductility elongation rates; and (10) Asphalt grade. It was found that mixing temperature, mixing time, rubber type, and asphalt grade all have significant effects upon the behavior of asphalt-rubber mixtures. Significant variability was also noticed in different laboratory batch replications. Varying laboratory test temperature and force-ductility elongation rate revealed further differences in asphalt-rubber mixtures.