Research On Gradation Design Of Asphalt Mixture In Hainan Based On High Temperature Stability

Compared with the cement pavement,Asphalt pavement has more advantages in driving comfort,flatness and maintenance convenience,andit has been widely used in highway surface in China,becoming the main pavement structure at all levels of highway in China.In recent years,the early destructive problems,encountered in the construction of our country due to the high temperature stability of asphalt pavement,have become one of the major problems that need to be studied and solved.Therefore,the factors,influencing the early damage of asphalt pavement,are investigated and studied,will play an important role in solving these problems.Because of special monsoon high temperature and rainy weather in Hainan Province,asphalt pavement disease complexity is quite different from other regions in our country Based on the high temperature stability,this paper studied the gradation design of asphalt pavement in Hainan Province.Firstly,Hainan the annual rainfall,the annual average temperature,days for above 30 temperature of one year and sunshine time was counted,analyzing the climate characteristics of Hainan.At the same time,relying on the rebuilding engineering,the study investigated and evaluated the asphalt pavement condition.Secondly,the temperature changes of the internal structure of the pavement were observed by embedding the temperature sensor in the asphalt pavement test section to study the relationship between the temperature and the asphalt pavement.The results showed that The daily temperature and the pavement surface temperature changed periodically and were almost synchronous,and the temperature of the road surface was much higher than daily temperature.There was a lag in the internal structure layer of asphalt pavement,and the greater the depth of pavement structure,the more obvious hysteresis.Thirdly,the study studied the gradation range of asphalt mixture engineering design in Hainan area again.Bythe relationship among the coarse aggregate bulk density test,the orthogonal Marshall test and the key sieve pass rate and dynamic stability of the mineral aggregate,Based on the standard recommended AC-13 and AC-20 engineering gradation scopes,this paper puted forward the engineering design gradation ranges which was suitable for the climate characteristic of Hainan.Finally,through mix proportion design of asphalt mixture and the comparison of asphalt mixture with high temperature stability for the recommended gradation ranges and standard grading ranges,the study found that the recommended gradation ranges were better than the standard grading range.Meanwhile,combined with the immersion Marshall test,freeze-thaw splitting test and seepage test,the study evaluated the performance against water damage and seepage performance of mixture,the recommended gradation ranges was far better than the standard design requirements in test results.Finally,Integrating Evaluation results of pavement performance of asphalt mixture,the recommended AC-13 and AC-20 mixture gradation range suited for the hot and rainy climate characteristics of Hainan,which could provide reference for other similar projects in Hainan area.