High Brittleness of High Strength Concrete and Failure Mechanism Under Impact Loading
The changes in compressive strength,flexural strength,and flexural compression ratio of high strength concrete(C60)and medium-low strength concrete(C30)with age were compared through experiments,and the failure mechanism of high strength concrete under impact loading was studied using micro computed tomography(Micro-CT)analysis technology.The results showed that compared with C30 concrete,at 3,7,28,56 d of age,the compressive strength of C60 concrete increased by 57.5%,53.7%,54.3%,and 52.8%,and the flexural strength of C60 concrete increased by 51.2%,39.6%,32.4%,and 21.7%,respectively.The increase in flexural strength of high strength concrete is lower than that of compressive strength,indicating that their brittle characteristics are obvious.The flexural compression ratio of C60 concrete is lower than that of C30 concrete,indicating poor toughness and high brittleness of C60 concrete.Under external impact loading,microcracks first appear in the weak interface transition zone of high strength concrete,and then expand into the interior of coarse aggregate to form aggregate microcracks.The aggregate microcracks continue to expand and connect with cement stone microcracks,ultimately leading to cracking and failure of concrete specimens.
万方数据
维普
