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.
NEW DECAPODS FROM THE NAVIDAD FORMATION (MIOCENE) OF CHILE
Abstract A new Miocene decapod fauna is described from the Navidad Formation of coastal Chile. The fauna includes five callianassoid taxa, none of which is preserved sufficiently to identify to species level. New species include Calappilia? chilensis, Hepatus spinimarginatus, Proterocarcinus navidad, Pilumnus cucaoensis, and Pinnixa navidadensis. A possible rhizopine member of the Pilumnidae Samouelle, 1819, is described. Trichopeltarion levis Casadío et al., 2004, previously known from the late Oligocene of western Argentina, was also recovered from these rocks. Calappa circularis Beurlen, from the lower Miocene Pirabas Formation in Brazil, is herein referred to Calappilia. This report greatly increases the known number of fossil decapods from Chile and sets the stage for paleobiogeographic comparison of the decapod faunas of Chile and Argentina.