Study On Mix Design Of Overburden Asphalt Mixture Considering Skid Resistance

In recent years,with the rapid development of highway construction,the traffic safety problem has been paid more and more attention by people,and the road traffic safety is closely related to the anti sliding performance of the road and the highway traffic accident is mostly caused by the pavement skid resistance.In view of the existing problem that the asphalt mixture design process has sigle evaluation of anti slide performance,it is necessary to add the skid resistant performance in the asphalt mixture design process,optimization the aggregate gradation,mix proportion design method,in order to ensure the mixture has good resistance sliding performance.In this paper,four kinds of commonly used asphalt mixture,such as micro-surface,ultra-thin wear layer,asphalt rubber hot mixture and drainage asphalt mixture,are designed consider to increase anti-skid performance,the suitable anti-skid performance evaluation index is proposed.The existing micro surfacing mixture design method is optimized,based on Petrina Tutumina Johannes method,proposed the micro surfacing mixture design method considering the anti slide performance;Through the comparison and analysis of the types of the commonly used ultra-thin abrasion,this paper adopts the variable I method to carry on the gradation design of the ultra-thin abrasive layer,and studies its anti-slip durability;through the comparative analysis of the existing rubber asphalt mixture gradation range,design rubber asphalt mixture by three kinds gradation SMA-13,AASHTO and AC-13,and study the influence of key sieve passing rate of 4.75mm on the anti sliding performance of rubber asphalt mixture;the existing drainage asphalt mixture design methods were analyzed,different clearance mixture of coarse value mix design,in order to study the influence of coarse aggregate coarse value on skid resistance of drainage asphalt mixture.Test results show that:when design the micro surfacingmixture mix,the use of anti rutting and anti sliding performance to determine the optimum asphalt in our standard method,and selection the best ratio aggregate ratio,the micro surfacing mixture has good anti sliding performance under optimum asphalt aggregate ratio;NCHRP441 model,VTTI model,NCAT model is used to derive the ultra-thin layer mixture structure depth estimates,NCAT derived model of ultra-thin layer mixture structure depth prediction accuracy is the highest,in order to ensure the mixture structure depth to meet the requirements,the recommended 4.75mm passing rate should not over 29.9%;4.75mm passing rate directly affects the rubber asphalt mixture anti sliding performance,the value of R2 between the two is over 0.934,when design the rubber asphalt mixture,the rubber asphalt mixture anti sliding performance is best when the recommended 4.75mm passing rate is 20%～30.8%;Using the three prediction model to estimate the drainage asphalt mixture construction depth,the value of R2 between NCHRP441 model and crude value is 0.9573,which is the highest of the three,adjusting the value of P4.75,Cc,Cu will improve the anti sliding performance of drainage asphalt mixture.