Analysis And Application Of Test Method For Concrete Dynamic Behavior

Researches in recent years indicate that there are distinct difference between the dynamic behavior of concrete and its static behavior. But nowadays the static mechanical parameters of concrete increased by several percent are used as dynamic mechanical parameter to appraise anti-earthquake safety of concrete structure. The primary reason for this is that there are few test researches on dynamic behavior of concrete, furthermore there is large differences in the test results. Due to the above reason, this paper would study dynamic behavior of concrete by tests based on the analysis and sum-up of test methods, and through numerical analysis.As a subtopic of project "Research of dynamic characteristics and damage mechanism of concrete ", which is funded by academician subject development fund of HoHai University. In this paper, firstly, applicable conditions and applicable range of different test methods are summarized and analyzed; then, a test scheme for concrete beams are developed, and applied to carry out static and dynamic flexural-tensile test and AE test of fully-graded concrete beam; finally, numerical analysis of SHPB test are carried out.This paper obtains some useful conclusions:1. different test methods for dynamic behavior of concrete are applicable in different strain rate range and for different load types;2. the test scheme proposed in this paper for the third-piont flexural beam is feasible and simple for use;3. results of hydraulic servo test indicate that dynamic flexural strength, Young's modulus, crack strain and maximal nominal flexural-tensile strain increase by about 30 percent compared with its static results of full-graded concrete;4. AE test indicates'that the damage process is in the order: the occurrence of interfacial cracks and extension into mortars, coarse aggregates rupture; the typical Kaiser effect and crack close occur in the dynamic test of full-graded concrete;5. with the increase in diameter and length of the bar, the wave dispersion effect becomes more and more obvious for SHPB test. As far as the specimens with same diameters are concerned, it takes more time for the stress in longer specimen to reach balance.