混凝土力学性能的应变率效应

针对混凝土材料本构关系具有明显的应变率效应,对混凝土材料在不同应变率下的力学性能进行了分析研究。总结了应变率对混凝土抗压强度、抗拉强度、弹性模量以及临界应变的影响,通过比较各拟和公式预测的动态增大系数以及文献中的试验数据,分析了各公式的适用条件和范围。结果表明：对于混凝土抗压强度,在不同的应变率范围内应采用不同的经验公式;对于混凝土抗拉强度,修正的CEB（欧洲国际混凝土委员会规范）公式与试验数据符合更好;应变率对弹性模量的影响较小,可采用CEB公式计算动态弹性模量;应变率对与极限抗压强度、极限抗拉强度相对应的临界应变值的影响需做进一步的研究。

Strain rate effect on mechanical properties of concrete

The strain rate has a significant influence on the mechanical properties of concrete,the strain rate effects on compressive strength,tensile strength,elastic modulus and threshold strain were reviewed and summarized.The dynamic increase factor(DIF) obtained from various empirical equations were compared with experimental results reported in the references in a wide range of strain rate.The results show that the DIF of compressive strength can be determined by different empirical equations according to the range of strain rate.The DIF of tensile strength obtained from modified CEB(Euro-International Committee for Concrete) formula is coincidenced with experimental results.The strain rate effects on the elastic modulus are much smaller than that on the tensile strength and compressive strength.The CEB formula can be used to predict the dynamic elastic modulus.The strain rates effects on the threshold strain corresponding to the compressive strength,tensile strength are needed to study further.5 figs,19 refs.