Study On Thin Overlay Technology Of Warm Mix Rubber Asphalt Mixture

In order to solve the problems of large consumption, serious pollution, poor performance and compaction difficultly of the traditional asphalt mixture efficiently, the paper combined rubber asphalt technology, warm mix technology and thin overlay technology together to study the warm mix rubber asphalt modified technology and the composition design with the pavement performence and the interfacial shear strength, product a kind of environmentally friendly asphalt mixture suitable for recovering the structure and function of pavement. Based on penetration-. softening point、ductility、viscosity、viscosity-temperature coefficient, combinedrange analysis and grey relational analysis, the suitable powder dosage, mixing temperature, mixing time, and warm mix agent content of preparing warm mix rubber asphalt are studied; Based on volume index’s change law of the warm mix rubber asphalt mixture, and refer to the requirements of technical specifications for construction of highway asphalt pavements, the compaction method and composition design flow are studied, then the pavement performance of variable fators are studied; Based on interfacial shear test, the suitable test method and pavement processing means are studied.Resullts show that the rubber powder dosage is the significantly factors of affecting asphalt performance, and then is the mixing temperature, the opitiumu modified technology is rubber content20%, stirring temperature200℃, stirring time75min, LQ-1106content0.6%;VVW, VMA of warm mix rubber asphalt mixture SMA-10are droped by decreasing compaction temperature, compaction times and asphalt content though compacting method of variable factors, but the VFA of the asphalt mixture is raised, all the indexes are changing quickly when the compaction temperature between140℃and150℃, and the extracting test results show that there is no great different of garadation changes between50compaction times and75compaction times, based on such results, the resonable forming method is compaction times75, asphalt content7.4%, compaction tempeature140℃are proposed, the construction temperature could reduce30℃compared with the hot hot-mix asphalt mixture; Different factors has different effects on the warm mix rubber asphalt mixture performance, the high temperature stability and low temperature crack resistance all improved after adding rubber powder, although water stability has a little lower, all meet standard requirements; There is a optimum dosage of rubber asphalt as bonding oil, which is2.0kg/m2. Shear strength has different change law under different construction techniques, but temperature is the most serious influence factor, the shear strength under60℃is only31.5percent of that under20癈, which reflect the interlaminar prones shear failure easily under the high temeperature, in order to improve the shear strength, it is suggested controling the TD of old asphalt pavement between0.7mm and1.3mm first, then molding by adopting the compact conditions of existing specifications after the old pavement temperature rised to softening point.