The Research For The Effect Of Gravel Aggregate Crushing Rate On The Performance Of Core Wall Asphalt Concrete

In the mix rate design of asphalt concrete, in order to ensure the adhesion of aggregate and asphalt and the mechanical properties of core wall asphait concrete. On the choice of raw materials, commonly select alkaline broken rock as coarse aggregate. But the alkaline rock in the Xinjiang region distribute lessly, some are away from the dam site thousands of kilometers, the broken rock cost highly and bring some environmental problems. In the Xinjiang area, the natural gravel aggregate distribute widely, can use local materials, convenient and economical. When select natural gravel as the coarse aggregate, in order to improve its mechanical properties, the specification suggest the coarse aggregate broken more than 50%. However, the amount of mortar in core wall asphalt concrete is more, partially or fully use the gravel crushing rock whether can effectively improve the performance of the core wall asphalt concrete, and its influence on the stress and strain of the asphalt concrete core wall dam, Need further experimental demonstration and calculation analysis.This paper consider mainly from two aspects of coarse aggregate crushing rate and asphalt mortar, analyzd asphalt mortar weaken the coarse aggregate broken bring the edge effect of asphalt concrete, reserched the distinct mechanical properties of asphalt concrete with different crushing rate, on the basis of, the ABAQUS software is used to carry out the engineering example finite element calculation, ascertained the stress distribution and displacement deformation of asphalt concrete core wall dam,the conclusion is as follows:(1) The asphalt mortar is greatly weakened the effect of coarse aggregate broken edges. The same crushing rate and asphalt content, the mechanical properties of the core wall asphalt concrete decreased with increasing concentration of mortar. The core wall asphalt concrete perform best when the asphalt mortar concentration is 2.0, the changes of mechanical index and porosity were not obvious when the asphalt mortar concentration is more than 2.0.(2) When the crushing rate of coarse aggregate respectively is 0%?50%?100%, and the tensile strength, permeability, water stability, static three-axis shear and other mechanical properties of the asphalt concrete are not very different. The strength of asphalt concrete composed of natural gravel aggregate is lower than composed of crushed gravel aggregate in the two tests of uniaxial compression and small beam bending, but satisfied the design requirements.(3) Through the finite element software calculation received, when the dam shell materials and transition materials are same, the dam's stress and strain is affected less by the coarse aggregate crushing rate. The displacement?stress?strain and shear stress level of the core wall are little different when the coarse aggregate crushing rate is 0% and 100%.(4) Natural gravel be used as the core wall asphalt concrete coarse aggregate, not only can ameliorate the peaceability of the core wall asphalt concrete, but also improve the antideformation capacity of the asphalt concrete core wall, and the mechanical properties also can meet the requirements of the standard.