Research On Reinforcement Technology Of Asphalt Mixture And Viscosity Reduction Technology Of Reinforcer In Hot-in-Place Recycling

This paper firstly takes the development status of road construction in China and the current national conditions and policies as the research background,then expounds the necessity of asphalt pavement recycling technology from the perspective of resource conservation and environmental protection,and then analyzes the applicability,advantages and disadvantages of four asphalt pavement recycling technologies.It is believed that the insitu thermal regeneration technology has unique advantages and the feasibility of popularization and application.Then,starting from the phenomenon of asphalt pavement aging,this paper points out that asphalt aging is the main reason for the degradation of asphalt pavement performance,and analyzes the regeneration mechanism of aging asphalt based on the asphalt aging mechanism.Based on the analysis of the aging asphalt regeneration method,it points out it points out the necessity of redundant reinforcement for the hot-in-place regeneration of the asphalt mixture.At the same time,this paper analyzes and summarizes the construction characteristics of the hot-in-place regeneration technology,including the regeneration process,recycling equipment,construction process and key quality control points,etc.,and points out the necessity of redundant reinforcement and viscosity reduction method for asphalt mixture hot-in-place regeneration.Then,based on the road performance and the applicability of the construction process,this paper compares the three commonly used redundant reinforcement technologies,and points out that the reinforcement is more suitable for the in-situ thermal regeneration technology,and determined the reasonable dosage and usage method of the reinforcing agent through experiments.In order to make the reinforcing agent better used in in-situ thermal regeneration technology,this paper uses an admixture with viscosity reducing effect to improve the thermal performance of low-density polyethylene,and used melting point,Vicat softening point,and melt index as indicators to evaluate the effect of the type and dosage of the admixture on the thermal performance of the reinforcing agent.According to the test results,four new reinforcing agents were prepared.The confirmatory test results show that the viscosity reduction effect of scheme 3,scheme 4 and scheme 5 is better.First of all,the reinforcing agent is mixed into the base asphalt to make modified asphalt through high-speed shearing.The three indexes,viscosity and rheological properties are measured to evaluate the influence of the reinforcing agent on the properties of asphalt with different viscosity reduction schemes.The results show that the admixture reduces the softening point,viscosity,dynamic shear modulus,and increases the penetration of the modified asphalt.The mechanism of the reinforcing agent is analyzed through microscopic tests.The mechanism of the reinforcing agent is analyzed through microscopic experiments.Then,the asphalt mortar was made into prism trabecular specimens for frequency scanning test,and the influence of different viscosity reducing schemes reinforcing agents on the viscoelastic properties of asphalt mortar was analyzed.The results show that the dynamic shear modulus values of scheme 1 and scheme 4 are higher,and the phase angle is lower,showing higher high temperature performance.Finally,the influence of different viscosity reducing schemes of reinforcing agents on the high-temperature anti-rutting performance,low-temperature anti-cracking performance,and water stability of asphalt mixtures is analyzed,the results show that compared with scheme 1,scheme 4 has a lower service temperature without significantly affecting the conventional road performance of asphalt mixtures.Therefore,scheme 4 is more suitable for in-situ thermal regeneration of asphalt pavements.