A Note on the Flexural Behavior of Concrete under Different Loading Rates

摘要

This paper examined the flexural behavior of large concrete specimens (300 × 300 × 1100 mm) under different strain rate. Four strain rates were examined: 10~(-6), 10~(-5),10~(-4), and 10~(-3) s~(-1). The changes of flexural strength, dynamically increased factor, as well as elastic modulus in response to different strain rates were well addressed. The results show that increasing strain rate led to more flattened surfaces of the specimens, In addition, more aggregates found to be broken on the fractured surface. The elastic modulus and flexural strength of the concrete were positively correlated to the strain rate. Nevertheless, the increase in elastic modulus was approximately half of the percentage of increase in flexural strength. There was no clear change for the Poisson's ratio in response to the change in strain rates.