Experimental Study On The Behavior Of Large Aggregate Concrete Under Dynamic Triaxial Compression-compression-tension Stress Stat

With the exploition and use of hydro energy, some very important hydraulic concrete structures, such as a large dam, large hydroelectric power stations and offshore oil drilling platform in China has been widely used. These large concrete structure in the process of the use, not only been effected by the static load, but also the complex dynamic multi-axis loads. But the researches on the dynamic perfor of concrete are mostly focused on the ordinary concrete, the study of the dynamic performance of the large aggregate concrete is almost blank. Therefore, the study on the dynamic multi-axis performance of large aggregate concrete under different strain rates and different stress ratio conditions is great significant.Based on the National Natural Science Foundation of China "the dynamic multiaxial test of large aggregate concrete and dynamic failure criterion in octahedral stress space" (ID: 51079019), the dynamic multi-axis performance of large aggregate and wet screened concrete under dynamic triaxial compression-compression-tension were studied experimentally. This experiment are carried out on a large static and dynamic triaxial test system in Dalian University of Technology. The four strain rates(10-5/s,10-4/s,10-3/s and 10-2/s) and seven kinds of stress ratio(0.1:-0.25:-1,0.1:-0.5:-1,0.1:-0.75:-1,0.1:-1:-1,0.05:-1:-1,0.2:-1:-1 and 0.3:-1:-1) are taken in the test. In this thesis, the main research work are present as follows:(1) The dynamic tests of large aggregate and wet screened concrete under uniaxial tension loading were carried out, studying the failure modes, ultimate tensile strength, the stress-strain curve, the critical strain and elastic modulus of concrete under different strain rates. According to the test date, the relationship between strain rate and ultimate tensile strength were established in the principal stress space. (2) The dynamic properties of large aggregate concrete and wet screened concrete under dynamic triaxial compression-compression-tension loading were researched experimentally. The influence of strain rate and stress ratio on the failure modes, ultimate tensile strength, the stress-strain curve and the critical strain of large aggregate concrete and wet screened concrete was analyzed. (3) The relationship of experiment performance between large aggregate and wet screened concrete was analyzed, under dynamic triaxial compression-compression-tension stress state. And the analyzing the relationship between dynamic triaxial experiment performance of large aggregate and wet screened concrete and their dynamic uniaxial experiment performance was analyzed.(4)Based on the test results of large aggregate and wet screened concrete under dynamic triaxial compression-compression-tension stress state, the dynamic failure criterion which consider the strain rate and stress ratio were established in the octahedral stress space.