Study On Asphalt Mixture Technology Of Steep Slope Road Section

With the mileages of expressway increasing, the expressway gradually extends to the mountain region. Due to the limit of terrain, Because the shearing strength of steep slope sections is insufficient, it is easy to cause early disease phenomenon of slippage,upheaval,rutting and so on. Based on the experience Marshall testing method can not reflect the material shear-bearing capacity, the existing standard also don't make the requests about shear-bearing capacity in mixture design. In view of the asphalt pavement of steep slope sections, the paper proposes the shear-bearing design of asphalt mixture to suit steep slope sections.The study first analyzes the shearing stress of asphalt pavement, the position and size of max shearing stress and the regularity changing with depth direction under the different vertical loads and horizontal loads; Then the study carries on the experimental analysis of max shearing strength of asphalt mixture through the different gradation, the different asphalt type, the different aggregate type, the different asphalt content, the different compactness, summarizes the general regularity of influencing shearing strength and carries on the contrast with rutting test; The paper conducts the analysis and research on mixture performance at high and low temperature before and after adding additives.Massive indoor tests show that asphalt is the main factor of affecting shearing strength, the max shearing strength increases with the asphalt equivalent softening point becoming higher; The aggregate characteristic has a remarkable influence on the mixture angle of internal friction; The mixture max shear strength achieves the maximum nearly at optimum asphalt content; The most shear strength increases with the compactness increasing and the porosity decreasing. We can improve anti-shearing ability through reducing the asphalt content or enhancing the compactness; In the steep slope sections, the imposing time of loads is long, adding the influence of high temperature, there will be larger shearing stress of asphalt mixture, so we should pay more attention to the shear-bearing design of asphalt mixture.