Study On Preparation And Performance Of Maintenance Materials For Permeable Air Voids In Asphalt Pavement

The rapid development of expressway construction has made a significant contribution to China’s economic development.However,due to material design and construction problems,the segregation of the asphalt pavement resulted in excessive local porosity.During service,it was easy to retain rainwater,which induced early water damage such as pits,pumping,looseness,etc.,which seriously affected the pavement service life.The existing treatment for segregation mainly uses slurry seal and micro-surface,but the cost is high and the sealing depth is limited.In some places,there may still be water seepage channels due to cracking,and currently commonly used pavement grouting materials are also not Applicable to the treatment of local large gaps.Therefore,it is of practical significance and engineering reference value to conduct research on maintenance and repair materials for the seepage gap of asphalt pavement.Based on the characteristics of permeable air voids,three types of asphalt pavement maintenance materials were designed and prepared;Through experiments,the influence of preparation process parameters on permeability and technical indicators was studied,It was determined that kerosene diluted asphalt was prepared according to a dilution ratio of 4:6;General emulsified asphalt prepared with E5 emulsifier has better comprehensive performance;Through the study of the effect of oil-water ratio,emulsifier content and penetrant content on the permeability of high-permeability emulsified asphalt,it is found that when the oil-water ratio of high-permeability emulsified asphalt is 45:55,emulsifier content is 1.5%,and penetrant content is 0.8%,The prepared high permeability emulsified asphalt has better comprehensive performance.The Study on the penetration mechanism of high-permeability emulsified asphalt shows that,Incorporation of penetrant,reduce oil-water ratio,and increase emulsifier content can reduce the surface tension and particle size of high-permeability emulsified asphalt,and improve the penetrability.The effect of void characteristics on the water stability and permeability coefficient of asphalt mixture was studied,and the critical void rate of asphalt pavement water damage was determined to be 8%;Specimens of asphalt mixtures with different permeable air voids were formed,the effect of the content of maintenance materials on the pavement performance was studied,It was found that the maintenance materials improved the residual stability,freeze-thaw splitting strength ratio and Water resistance of the mixture.Among the three types of treatment materials,high-permeability emulsified asphalt has the best effect on improving the road performance of asphalt mixtures,when the void ratio is 8%,the recommended dosage is 1.5L/m~2;when the void ratio is 12%,the recommended dosage is 2.0L/m~2.The effect of the content of maintenance materials on the skid resistance of the asphalt mixture specimen was studied,the results show that the texture depth and british pendulum value of the asphalt mixture specimens decrease with the increase in the amount of treatment materials.After the maintenance materials are painted,silicon carbide can be sprinkling to increase the british pendulum number of the asphalt mixture specimen.The recommended amount of sprinkling is 3.0kg/m~2.