Investigation Of Asphalt Pavement Structure On Large Longitudinal Slope

According to our country's road network plan, highway construction will be focus on the west region, because the western area is multitudinous, decided by the terrain landform, many roads are long and steep . Pavement damage was speed up by these factors. Therefore, special pavement structure shoule be researched basis on the stress characteristic.The vehicles power factor was resesrched based on vehicles performance change and biological fuel starting in this article, the special pavement design was proposed deepend on the reference slope value.These asphalt pavement failure have three main damge mode: rutting, broaching, water damage. The reason was aborated, the stress variation characteristic was analyzed under the different ambient condition, for many drivers loved to pour water on the brake, so early time water damage of pavement must be prevented. According to the existing research results, the basic mentality was proposed to solute the three kinds of pavement damage.For use the biggest performance of various structures fully, LSM flexible base, AC-20C middle layer and SMA upper layer was proposed,whose basis lies in: the SMA system is extremely mature, it's performance is stable, has the good anti- rutting, anti- broaching, anti-water damage capability; The shearing stress of the road surface and broaching can be reduced by the LSM flexible base; AC-20C serves as the upper layer not only to meet the performance need but also to be able to save the cost.Because limestone and silicarenite reserves rich in our country west, high qualityasphalt was choiced, forms eight kind of combinations to carry on the contrast experiment. Kinds of testing was be used to determinate the gradation and the best asphalt-aggregate ratio of mixture.In the confirmation stage, the single axle penetration experiment and the direct shear test was used to confirm the anti- rutting ability, anti-water damage capability and anti- broaching ability.The results showed that:1,The combination of LSM flexible base, AC-20C middle layer and SMA upper layer may satisfy the performance demand.2,When use the SBS modified asphalt in AC-20C middle layer ,the performance is most superior.3,The squash value of limestone is oversized, so it is not suitable the demand of SMA upper layer.4,The overall performance of SMA-16 upper layer (SBS modified asphalt + silicarenite) is best.