Research on polyurethane/nano-ZnO composite modified asphalt and its mixture properties
In order to improve the road performance of asphalt pavement,polyurethane/nano-ZnO composite modified asphalt was prepared by polyurethane,nano-ZnO and matrix asphalt.Taking penetration,softening point,ductility and 135 ℃ viscosity as evaluation indexes,the influence of modifier on asphalt performance was studied,and the storage stability was evaluated by softening point difference.Three kinds of composite modified asphalt AC-13C mixture were prepared for rutting test,trabecular bending test and immersion Marshall test to study the performance of modified asphalt mixture.The results show that the incorporation of polyurethane and nano-ZnO can significantly improve the high and low temperature performance of the matrix asphalt,and the storage stability meets the requirements of the specification.The composite modified asphalt mixture can meet the road performance of asphalt pavement.The modified asphalt mixture with 5%polyurethane and 3%nano-ZnO content has the best effect on improving high temperature performance and water stability.Compared with the matrix asphalt mixture,the dynamic stability is increased by 2.32 times,the residual stability is increased by 9.0%,and the maximum flexural tensile strain(-10 ℃)is increased by 8.3%.Considering the improve-ment effect of road performance,it is recommended to use 5%polyurethane compound 3%nano-ZnO as the best content of composite modified asphalt and its mixture.