Research And Design Of New High Performance Cold Repair Material For Pothole

Pit disease is the most serious disease in many diseases of asphalt pavement.Its damaged area is large,which is not conducive to driving safety.Among them,the more difficult is to repair the pits of asphalt pavement.Asphalt cold repairing material is widely used because of its advantages such as easy to use,all-weather repairing,simple and fast construction,energy saving and environmental protection.But the development time of cold filler is short,especially for solvent-based diluted asphalt cold filler,its initial stability is low,high temperature performance is poor,and water resistance is not good.Some domestic solvent-diluted cold patching materials have low product quality,poor durability and short service life.They often need to be repaired twice in a short time after repairing.And people only pay attention to cold repair materials,but neglect the repair effect of the pit interface.Because of poor bonding,the repair interface cracking is also one of the most common types of secondary damage after the pit repair.In view of the existing problems,this paper starts from the bond repair of the pit-slot interface,develops an efficient bonding agent for the pit-slot interface through the tensile shear test,and through the interlaminar shear test and interlaminar pull-out test,analyses the influence of its dosage,ambient temperature and interfacial forming humidity on the bond performance of the pit-slot wall.Finally,the crack resistance test is carried out.and the comprehensive evaluation of the pit-groove interface binder is made.The results show that the developed binder has high bond strength and good crack resistance.Then,considering the low temperature repairing effect and poor high temperature performance of the existing solvent dilution cold repairing material,a kind of warm mix cold paving asphalt cold repairing fluid and its mixture cold repairing material are developed.Firstly,starting from the cold fluid replenishment performance test,considering the excellent curing performance of polyurethane,polyurethane prepolymer was selected to modify it.Firstly,the cold fluid replenishment diluent and the content of polyurethane were tested,and the dosage range was determined.Then,the cold fluid replenishment formula was designed by orthogonal test,drawing test and shear test were carried out to analyze the bonding properties of polyurethane prepolymer.The construction and workability are analyzed by workability test,and the strength performance of the mixture is analyzed by Marshall stability test.Finally,the optimum scheme is selected as the binder ratio of the normal temperature cold repairing material.With this ratio,the suitable structure type of the new type of cold replenishment developed in this paper is discussed.The gradation structure and void fraction of asphalt mixture are studied.The commonly used LB-13,AM-13,AC-13 and SMA-13 structure types are selected as the test objects to determine the optimum gradation structure of cold replenishment.Empirical formula method was used to determine the optimum dosage of cold repairing asphalt liquid through workability test and initial Marshall stability indoor test.Finally,the storage construction and workability,strength forming rule,water stability,high temperature stability and low temperature crack resistance of the new cold-repaired asphalt mixture are tested and analyzed.In addition,the durability of the cold-repaired asphalt mixture is defined.The high temperature water stability is defined as the durability test index,and the performance of the cold-repaired asphalt mixture is compared with that of the related cold-repaired products.The results show that the new cold repairing asphalt mixture has the advantages of high initial stability,fast strength forming,high final strength,good water stability and excellent high temperature performance.