The Research Of Mixture Asphalt Shear Performance And Analysis Of Factors Affecting

Asphalt pavement consists of surface course and all kinds of base course and bed course constructed by asphalt material and mineral aggregate. It is wideiy used in road engineering, with the advantages of non-joint, good-flatness, low-noise, small-vibration,short-constructionterm,convenience of maintenance and beautiful shape. The main causes of asphalt pavement destruction include :one is high-temperature destruction with shortness of shear strength or excessiveness of plastic deformation in summer;the other is low-temperature cracking with shortness of tensile strength or low anti-deformation ability resulted by slowness of stress relaxation modulus reduction. The third is fatige destruction ,which stresses produced on the loads exceed anti-structural force after loads effection times overpass some times.Currently,there are three main test methods to evaluate the high-temperature performance of bituminous mixture:tri-axial compaction test,single -axial creep test,rutting test.But they have certain limitations in evaluating the high-temperature performance of the asphalt mixture. This paper analyzes the reasons why permanent distortion forms mainly by using the single shear test apparatus,and points out that the shear stress of the mixture is mainly caused by the readjusting and shear flowing of the aggregate when subjected to traffic load.High-temperature shearing strength of asphalt mixture lies on cohesive force and friction angleΦof asphalt mixture. Friction angle mainly lies on mineral gradation,grain shape ,surface characteristic , thickness of asphalt and so on;and cohesive force mainly lies on asphalt performance and interaction between asphalt and mineral. At the same time, facters impacting high-temperature shearing strength mainly include mineral aggregate characteristic,gradation, asphalt performance, interaction of asphalt and mineral ,pavement structure and climate condition. These analyses the influence of shearing ability of asphalt mixture ,which consideres five facters including gradation style, asphalt-aggregate ratio,compactness,temperature, loading rate .Papers sheared test on the asphalt mixture shear capacity of the study and its impact on the shear properties of the factors, abstain the main conclusions as follows:1. A dynamic modulus was selected. Through investigations Library, AI calculations, testing, data return of four methods, comprehensive and objective evaluation to determine a reasonable asphalt mixture under different conditions-money, to design accurate and reasonable value . When a test conditions and material properties parameters, the test should be determined by the dynamic mixture of asphalt-money when the same has been part of asphalt mixture results of the trial, the parameters included in the pilot has done the test conditions Within the scope of, can be linear regression approach to the reunification of the formula to calculate the asphalt mixture of dynamic modulus; did not test dynamic modulus of the test conditions, have been testing the nature and asphalt mixture of asphalt the size parameters, SHELL design used in the investigation Connaught Jammu map of the United States or asphalt Association (AI) method determine the design of asphalt mixture of die-money. But a different approach, that the dynamic modulus of the results may have some differences. Therefore, the combination of four methods to use reasonable by the dynamic mode money before more accurate.2. Shear test and a performance of the shear. Papers from raw material properties, shear stress analysis, rational mode of composition, materials shear tests, the experimental results of the five components of the note, from a mixture of asphalt Shencengcishang shear properties of the study, because Asphalt mixture of temperature, aging of the impact of changes in its mode of larger magnitude, resulting in its force in nature, from the shear test start, determine a reasonable mode of composition, so that the shear layer of asphalt to reduce response.3. In the impact analysis of the parameters on the shear test, the papers did a major asphalt mixture on the five areas: graded type, Whetstone ratio, degree of compaction, temperature, loading rate. These five factors for the asphalt mixture of shear properties have a greater influence.