Study On Preparation And Performance Of Asphalt Pavement Joint Sealant

As one of the main diseases of asphalt pavement,crack will lead to the decrease of pavement bearing capacity and seriously affect the driving comfort and safety.Glue filling is an effective way to repair cracks.The performance of potting glue directly affects the maintenance level and durability of road surface.However,the quality of commercially available sealant is uneven and its fatigue resistance is poor.Therefore,it is of great significance to research and develop sealant materials with excellent performance and fatigue resistance.In this paper,starting from the preparation of sealant materials,through orthogonal experimental design to determine the material composition design of sealant,namely the ratio,with the help of the adhesive,rheological and anti-fatigue properties of sealant to further optimize the mix ratio of sealant.At the same time,ABAQUS software was used to analyze the actual stress state of potage adhesive on asphalt pavement,and the mechanical response of potage adhesive under the coupling effect of temperature and load was simulated.The main research contents and results are as follows:Firstly,the composition of sealant was analyzed.The preparation technology and admixture amount of sealant were obtained through coning degree,softening point,flow test,elastic recovery rate and low temperature tensile test.The composition design and ratio of sealant materials were optimized by using orthogonal experimental design and range analysis method,and two ratios of sealant were determined.Ratio 1 was 40%compatibilizer,15% toughening agent and 30% diluent.Ratio 2:40% compatibilizer,25%toughening agent,30% diluent.Then,based on the surface free energy theory and 45° oblique shear test,the adhesion and shear properties between the cracks were studied.Temperature scanning and frequency scanning were used to study the rheological properties of potting glue before and after aging by means of rotary film oven aging and pressure aging.LAS fatigue test and VECD theoretical model were used to analyze the fatigue properties of potting adhesive before and after aging.It is concluded that the best ratio of filling glue is ratio1.Matrix asphalt and epoxy modifier mixed solution: compatibilizer: toughening agent:diluent = 1:0.4:0:15:0.3.Finally,the finite element software is used to simulate and analyze the actual mechanical response of potting glue in pavement.The atmospheric temperature and pavement performance in northwest China were analyzed,and the ABAQUS finite element model was established to analyze the most adverse tensile stress and shear stress of the cement-pavement material under the coupled action of temperature and load,and the values were compared with the allowable tensile stress and shear stress in the theoretical formula.The study says: After adhesive treatment,the most adverse tensile stress and shear stress of pavement under the coupling action of load and temperature are0.091 MPa and 0.091 MPa,which are less than the maximum allowable tensile stress of0.224 MPa and the maximum allowable shear stress of 2.856 MPa.The results show that the asphalt pavement treated by the sealant can work normally under the coupling action of temperature and load without cracking.