Experiment Study On The Mechanicai Properties Of Low Temperature Concrete Under The Dynamic Loading

In recent years, the development of social economy has led to the rapid construction of the national railway, highway, bridge, port, tunnel, subway, municipal and other infrastructure, the application of concrete engineering materials more widely, more and more. In northern China and western cold regions and some cryogenic complex environment construction, to ensure the engineering quality must also be fully grasp the physical and mechanical properties of concrete under the condition of low temperature, including the low-temperature impact resistance.In the laboratory preparation of concrete materials, preparation of test blocks and specimens, in the TYE-2000 type pressure testing machine for static mechanical tests, test the static mechanical properties of concrete materials; The dynamic mechanical properties of concrete samples under different temperatures were analyzed by using the large rod diameter SHPB 74mm experimental device under normal temperature and different low temperature impact test.Through the analysis of the experimental data, it is concluded that:â‘  The failure strength of concrete is greater than that of static load when the dynamic load is dynamic;â‘¡ When the freezing temperature is the same, the maximum failure stress of concrete specimen is similar, and the latter is slightly larger than that of the former;â‘¢ As the temperature decreases, the water in the pores and joints in the concrete material is reduced, and the brittleness of concrete is strengthened, and the shape of the concrete is gradually destroyed; On the other hand, the moisture content of the same time, increasing the moisture and aggregate, aggregate and aggregate the glue between the strength and cohesion, resulting in concrete compressive strength increases, the maximum stress increases when the damage occurs.The experimental study reveals the evolution mechanism and dynamic stress-strain response of low temperature concrete under impact loading, which provides a useful reference for the design and construction of concrete under low temperature.