Study On The Pavement Performance And Application Of The High Modulus Asphalt Concrete Base On Ethiopia AA Highway

In recent years,our highway cause has achieved an incredible run of success.However,because of the combined effects of the rapid growth of the traffic volume,the increase of the automobile's load,and the high frequency of the extreme climate,the early damage of the asphalt pavement is quite serious,especially rutting damage,which has become the most common damage of the asphalt pavement.To solve this problem,a large number of studies have been performed by many road workers all around the world.It is found that the High Modulus Asphalt Concrete(HMAC)is a kind of materials with excellent high temperature stability performance,which is usually used for improving the rutting performance,especially when it is used in the asphalt under layer.Based on the high modulus asphalt concrete base project in Ethiopia AA highway,this study does research into the performance of the HMAC from the gradation composition design and the pavement performance.Firstly,supported by the project,the raw materials are tested,and the wet modified method was adopted to prepare the HMAC.In addition,the modification technology of the new-type HMAC was summed up.Secondly,based on the results of the AA highway pavement structure,the gradation design principle for HMAC-25 adopted in the pavement base was introduced.Moreover,the filling experiment was adopted to design for the coarse aggregate,and the i method was adopted to design for the fine aggregate.Then,the gradation was optimized through filling experiment and Marshall test,and the reasonable gradation range of the HMAC-25 was finally obtained.In addition,the mean curve of the reasonable gradation range of the HMAC-25 was chosen,and various tests were conducted with 0%,0.3%,0.6%,0.9% high modulus additive respectively.Finally,the optimum mixing amount of 0.45% was decided with the help of the grey correlation analysis.Thus,the determining method for the optimum mixing amount of the high modulus additive-the grey correlation determining method.Besides,the upper limit,the mean,and the lower limit curves of the reasonable gradation range of the HMAC-25 was chosen,and certain amount(0% and 0.45%)of high modulus additive was added.Then,the high temperature performance,the water stability performance,the cryogenic property and the mechanical property were analyzed to the high modulus asphalt concrete with different gradation and different adding amount.Therefore,the suggested range of the technical standard of the high modulus asphalt concrete.Finally,the advantage of the HMAC pavement performance was verified through paving the Ethiopia AA highway.And the HMAC construction technology was summed up,which will provide experience for the application and promotion of the HMAC used in the base project.