Study On Road Performances Of Cross-linked Polyethylene Modified Asphalt Mixture

Disease of asphalt pavement is easily induced by the coupling effect of various factors including temperature,vehicle load and water etc.,hence asphalt pavement performance and service life are greatly impaired.One of the main ways to improve the performance of asphalt and its mixture is to modify asphalt.The traditional modifier has some limitations in the modification effect,application environment,economic benefits and environmental protection.Therefore,the new modifier is explored and the performances of the modified asphalt mixture are studied.The theoretical basis is applied to the practical engineering of the modified asphalt mixture.In this paper,asphalt mixture was prepared based on cross-linked polyethylene.The properties of its high temperature stability,low temperature crack resistance,fatigue properties and water stability are investigated by single-axis creep test,indirect tensile test,four-point bending fatigue test and freeze-thaw splitting test.Creep stiffness modulus,splitting tensile strength,fatigue life and freeze-thaw splitting strength are used to evaluate the performance.Compared with matrix asphalt,PE modified asphalt,SBS modified asphalt mixture,the advantages and disadvantages of XLPE modified asphalt mixture are obtained and the influence of XLPE content on road performance is also studied.The results show that in terms of high temperature performance,the elasticity of asphalt is obviously increased by the incorporation of XLPE and the high temperature modulus of the asphalt mixture is improve;in terms of low temperature performance,splitting strength of XLPE modified asphalt mixture is better than matrix asphalt and PE modified asphalt,Therefore the low temperature performance of asphalt mixture can be improved by XLPE;in terms of fatigue performance,the addition of XLPE in the asphalt significantly reduced the fatigue life of its mixture and the bending stiffness modulus of the decay rate;and in terms of water stability,the adhesion degree of XLPE modified asphalt and aggregate is 5,and the tensile strength of the mixture 1s 92.9%,which indicates that the stability of XLPE modified asphalt mixture is better.Given the above,the use of XLPE as the asphalt modifier can significantly enhances the road performance of the asphalt mixture,but the content of XLPE is the key factor affecting the road performance of asphalt mixture.The road performance of the XLPE asphalt mixture is strengthened firstly and then weakened with the increase of the content and when the content of XLPE is 5%the road performance is best.