Study On Pavement Performance Of High Modulus Asphalt Mixture Under Water-High Temperature Coupling Conditions

Asphalt pavement is widely used in China’s road construction due to its good driving comfort and excellent performance.However,with the rapid development of China’s economy,the requirements for road construction are getting higher.In recent years,Chinese road workers introduced the concept of high modulus asphalt mixture to improve the rutting resistance and fatigue resistance of asphalt pavement,and carried out a lot of related research,and achieved a series of research results.However,the long rainy season and the heavy rainfall in some high temperature areas in China will have an important impact on high modulus asphalt mixture.But there are few studies on the pavement performance of high-modulus asphalt mixture under the action of water,which restricts the further application and promotion of high-modulus asphalt mixture technology.In view of this,on the basis of fully investigating the existing research,the pavement performance of high modulus asphalt mixture under Water-high temperature coupling is studied in this paper.The influence of temperature,moisture,high modulus agent,gradation and other factors are analyzed.The Deterioration of high modulus asphalt mixture performance under Water-high temperature coupling is revealed.The main conclusions are as follows:(1)The raw materials used in asphalt mixtures were tested,and the mix ratio of high modulus asphalt mixtures and base asphalt mixtures was designed with the raw materials meeting the requirements.The optimum asphalt-aggregate ratio of each admixture asphalt mixtures and base asphalt mixtures was found.(2)The relationship between water content and immersion time of three kinds of high modulus asphalt mixtures and base asphalt mixtures with AC-13 gradation and AC-16 gradation was tested at 40~60C.The results show that the addition of admixture does not affect the relationship between water content and soaking time.The higher the temperature,the longer it takes the asphalt mixture to reach 100% moisture content,and the more water absorption it absorbs.Ac-13 and ac-16 stages absorb more water and take longer time to reach full water state.Finally,the time corresponding to 50%,80% and 100% moisture content of AC-13 and AC-16 graded asphalt mixture at 40 ~60 ~C is used as the time basis for subsequent rutting test and fatigue performance test.(3)Under 40 ℃ and 60 ℃ for two kinds of gradation,three kinds of admixture,two kinds of maintenance conditions carried out rutting tests of RA,PR.M,BRA and base asphalt mixture respectively,it is found that the increase of temperature will reduce the dynamic stability of asphalt mixture,and the increase of temperature will obviously accelerate the reduction speed of the dynamic stability of high modulus asphalt mixture,and the thermal insulation time will affect the dynamic stability of asphalt mixture.The dynamic stability of RA asphalt mixture is higher than that of PR.M and BRA under any condition,and the decline rate of dynamic stability is the slowest.The rutting depth of RA asphalt mixture is obviously lower than that of PR.M and BRA according to the rutting depth data.Whether in AC-13 or AC-16 gradation,the decline rate of dynamic stability of all asphalt mixture after immersion is greater than that under non-immersion condition.With the increase of immersion time,the decline rate of dynamic stability of AC-16 graded asphalt mixture increases,and the thermal insulation time also has a great influence on the dynamic stability of asphalt mixture;with the increase of time,the influence of water on asphalt mixture decreases gradually;under the Water-high temperature coupling condition,the damage of high temperature performance of asphalt mixture is greater than that of temperature on asphalt mixture.Damage to high temperature performance.(4)The three-point bending fatigue life test was carried out under the same conditions as the rutting test.It was found that the fatigue life of the three kinds of high modulus asphalt mixtures decreased faster than that of asphalt mixtures under the condition of water-high temperature coupling when the temperature increased.The results show that the effect of temperature on fatigue life is smaller than that of water-high temperature coupling condition.The decrease rate of fatigue life of three kinds of high modulus asphalt mixture is less than that affected by temperature when the stress ratio increases.After analyzing the data,the stress and fatigue equations and curves under the corresponding conditions are fitted.(5)For RA high modulus asphalt mixture,through the low temperature trabecular bending test,residual stability test,freeze-thaw split test,found that it has excellent high temperature temperature and fatigue performance,low temperature crack resistance and water stability can also meet the technical requirements.(6)By using Apbi software,the structure of inorganic binder,asphalt binder and granular pavement is designed,and the best surface layer,medium surface layer,lower layer thickness and modulus of the three types of pavement are determined,and the best high modulus asphalt layer level in the three structures is found.