Research On Pavement Performance Of Rubber Asphalt Concrete In Cold Region

Rubber modified asphalt is one of the commonly used modified asphalt.The rubber particles with different sizes which were obtained by processing the waste rubber tires can not only improve the road performance and durability of asphalt concrete,the stability of asphalt concrete but also provide an effective way to recycle the waste rubber tire,which has important environmental protection value and social economic benefit.Although there has been related research on the rubber powder modified asphalt performance,but the rubber powder modified asphalt performance factors and the performance evaluation of the mixture has not formed unified.In order to understand the factors of the performance of modified asphalt rubber powder clearly,and preparation of rubber powder with better performance of modified asphalt mixture,the following contents are mainly studied in this paper.Firstly,the modification mechanism of crumb rubber modified asphalt was analyzed by means of density analysis and blending analysis,finding that rubber powder not only the physical adsorption and chemical swelling effect,but also the form of a stable system ultimately during high-temperature mixing.The rubber powder modified asphalt high shear mixing process which taking the penetration,softening point,extension degree and elastic recovery performance as the evaluation index were studied by means of orthogonal experimental design method,the preparation technology of rubber powder modified asphalt was obtained that shear rate is 7000r/min,shear time is 75 min,shear temperature is 180?.Secondly,The experiment from four aspects of rubber powder content,mesh,the source of plastic and asphalt type were studied which index as penetration,softening point,viscosity,extension degree and elastic recovery performance in order to analysis on the influence factors of rubber powder modified asphalt performance systematically.It is found that the asphalt mixture can effectively improve the performance of asphalt pavement,enhance its high temperature stability and low temperature crack resistance,and inhibit the occurrence of aging reaction,and improve the service life of asphalt pavement.based on the results of analysis of variance,the rubber powder content and number of significant influence degree.Finally,In order to evaluate the performance of crumb rubber modified asphalt mixture,rutting test,low temperature bending test of small beam,freeze-thaw splitting test,cantabro test,residual stability test and bending fatigue test were be tested to analysis of rubber powder modified asphalt high temperature stability,low temperature crack resistance,water stability and fatigue properties,and with the matrix asphalt mixture and compare with SBS modified asphalt mixture performance,It is found that the whole performance of asphalt mixture is improved after blending with rubber powder,and closing to that of SBS modifier.