Detection method of water stability of cold region large-grain-size asphalt mixture

Abstract

The invention belongs to the road engineering technical field, and in particular, relates to a detection method of water stability of a cold region large-grain-size asphalt mixture. The detection method comprises the steps: firstly, carrying out rolling compaction on the large-grain-size asphalt mixture into two plate block specimens, and cutting each plate block specimen into 6 small prismoid beam specimens; randomly selecting 3 specimens from the 6 small prismoid beam specimens of each plate block specimen, and forming an A group and a B group; making 6 specimens of the A group not soaked in water, making 6 specimens of the B group placed under freeze-thaw conditions, carrying out bending tests on the two groups of specimens, measuring the freeze-thaw flexural-tensile strength ratio BSR[dr] and the freeze-thaw flexural-tensile failure strain ratio FSR[dr] of the specimens, and when the average freeze-thaw flexural-tensile strength ratio BSR[dr] and the average freeze-thaw flexural-tensile failure strain ratio FSR[dr] of the two groups of specimens are both greater than or equal to 85%, considering that the water stability of the large-grain-size asphalt mixture is good. The method solves the problems of specimens molded by a traditional Marshall compaction testing method, and puts forward a new water stability testing method integrating the low temperature stability and the water stability of the asphalt mixture.

Description

technical field [0001] The invention belongs to the technical field of road engineering, and in particular relates to a method for detecting the water stability of large-particle-diameter asphalt mixture in cold regions. Background technique [0002] my country's current highway asphalt pavement construction technical specifications divide the extreme minimum temperature from -37.0 to -21.5°C into cold areas according to the design low temperature zone. In the industry, the mixture with the nominal maximum particle size of the aggregate greater than 19.0mm is called large particle size asphalt mixture. material. In my country's current "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering" (JTGE20-2011), the freeze-thaw splitting test method is used to test the water stability of asphalt mixtures. The test piece is tested, and the problems are as follows: [0003] (1) There are differences between the test piece forming and the actual construction process...

AI Technical Summary

Problems solved by technology

Only relying on the Marshall compaction instrument to compact the formed test piece cannot truly reflect the rubbing and rolling effect of the road roller and the vehicle load on the asphalt pavement, which is quite different from the action of the asphalt pavement under construction and use, and the Marshall test piece Compaction is not closely related to traffic volume

[0004] (2) The forming method of the test piece cannot simulate the driving compaction

There is a big difference between the forming process of the Marshall specimen and the actual compaction of the road. The horizontal shearing effect of the load is not considered, and the compactness of the mixture is only increased by increasing the number of compactions. Crushing of materials, change of mixture gradation type

[0005] (3) Not suitable for asphalt mixture molding with large particle size aggregates

[0006] (4) The splitting test data is more discrete and the accuracy is lower

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