Asphalt mixture mineral aggregate gradation composition design method using internal friction angle as design index

Abstract

The invention belongs to the technical field of traffic civil engineering application, and particularly relates to an asphalt mixture mineral aggregate gradation composition design method using the internal friction angle as a design index. A stage-by-stage filling theory is used; materials with the lower stage of particle diameter D1 are filled into maximum-nominal-size NMAS; by measuring the internal frictional angle phi of aggregates at different proportions, the proportion corresponding to the maximum internal frictional angle is used as an optimum composition proportion for forming the mineral stable framework; by such analogy, the optimum composition proportion relationship of each grade of coarse aggregates in the asphalt mixture can be obtained, so that a stable coarse aggregate framework structure is formed. Then, a bailey method is used for designing the fine aggregate and filling material proportion; the mineral aggregate gradation designed by the method provided by the invention realizes shearing resistance and compactness. The method has the advantages that the targeted performance is good; by aiming at the physical damage features of track damages of the asphalt pavement in Guangxi high-temperature hot and humid area, i.e., the insufficient high-temperature stability, the track-resistant asphalt mixture mineral aggregate gradation is designed; the mineral aggregate gradation has a stable framework compact structure.

Description

technical field [0001] The invention belongs to the application technical field of traffic civil engineering, and specifically relates to a method for designing the gradation composition of asphalt mixture and mineral material with the internal friction angle as the design index. Background technique [0002] The inventor has investigated the use of asphalt pavements on expressways in Guangxi: Nanyou Road, Pingzhong Road, Nanbai Road, Longbai Road, etc. The common pavement disease of several expressways is that the asphalt mixture is resistant to shearing. Mobility rutting caused by insufficient strength. Judging from the core sample structure of the pavement, the mixture is basically a dense skeleton structure, but rutting still occurs. There is a very important reason for this is the migration of the mixture skeleton, that is, the dense structure of the skeleton of the mixture is unstable. A large number of scientific research results and engineering examples show that t...

AI Technical Summary

Problems solved by technology

The design is often carried out according to the gradation range recommended by the code, but the gradation composition range given by the code is relatively wide. In order to obtain a dense skeleton structure, a gradation curve close to the lower limit of the gradation is often selected. The selection of this gradation curve is arbitrary. It is easy to cause too much particle content of the next particle size in the coarse aggregate, which will stretch the skeleton, and then affect the stability of the skeleton structure. The stable skeleton structure migrates, which eventually leads to shear deformation of the pavement; or the content of the next-level particle size is too small to achieve a stable skeleton structure

In both cases, the excellent performance of the dense structure of the skeleton cannot be maximized.

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