Study On Performance Of Waste PP/SBR Composite Modified Asphalt And Its Mixture

With the continuous development of China’s road industry,the requirements for pavement performance have also increased.In order to prevent early damage of the pavement,enhance the high and low temperature performance and water stability of the pavement,add an appropriate amount of modifier to make up for the lack of matrix asphalt to improve asphalt performance.Waste polypropylene plastic(PP)has good chemical resistance,elasticity,toughness,heat resistance and corrosion resistance.It can be dissolved in asphalt at a high temperature and distributed in a homogeneous phase,improving the high temperature performance of asphalt.The rubber modifier styrene-butadiene rubber(SBR)has good compatibility with asphalt,and it has obvious improvement on the low temperature performance of asphalt,which can enhance the low temperature crack resistance of the mixture.Composite modification of asphalt with two materials not only improves the high and low temperature performance of asphalt and mixtures,but also alleviates the environmental pollution problem to a certain extent,makes full use of renewable resources,and maximizes the use of resources.The study explores the use of waste polypropylene and styrene-butadiene rubber composite modifiers to improve the performance of asphalt,and at the same time to reduce the pollution of waste plastics in China.The optimum preparation process of composite modified asphalt is determined by the swelling process,shearing process,development process,and the amount of PP and SBR modifiers.The performance of PP/SBR composite modified asphalt was studied by three major index tests of asphalt,rotational viscosity test,dynamic shear rheology test and bending creep stiffness test.The rutting test,low-temperature beam bending test,water immersion Marshall test and freeze-thaw splitting test were carried out for the modified asphalt mixture made by the best preparation process.The high-low temperature and water stability performance of PP/SBR composite modified asphalt mixture were analyzed according to the test results.The research results show that the PP/SBR composite modified asphalt prepared under the optimal preparation process conditions has excellent high temperature performance and temperature sensing performance.At the same time,the low temperature performance of the matrix asphalt is also improved by the composite modifier.The high temperature rheological property of the composite modified asphalt is improved obviously,and the low temperature creep property is good.The high temperature stability of asphalt mixture is significantly improved,the low temperature performance is improved,and the water stability is excellent.