关键词: 混凝土, 动态性能, 侧压力, 应变速率, 劈拉强度, 本构模型

Abstract: Dynamic splitting tensile test under varying lateral pressure was conducted to simulate the actual stress state of concrete structures under earthquake and other dynamic loads. The variations of concrete’s splitting tensile strength, peak strain, and elastic modulus against strain rate and lateral pressure were examined in depth, and Mazars’ splitting tensile constitutive model was modified based on statistical distribution theory. Results suggest that the variations of mechanical properties of concrete under splitting tension and lateral pressure still display strain effect: increases in strain rate and lateral pressure could both enhance the splitting tensile strength and splitting modulus of elasticity; with the climbing of lateral pressure, the dynamic peak stress of concrete firstly reduced but then augmented. The modified constitutive model could well fit the dynamic splitting tensile stress-strain curves of concrete under different lateral pressures. The fitting parameter c of the upward segment of the stress-strain curve is affected by both strain rate and lateral pressure, while parameters A_T and B_T of the downward segment mainly depend on test conditions. Comparisons with data obtained by other scholars reveal that the modified model is of good suitability.

Key words: concrete, dynamic properties, lateral pressure, strain rate, splitting tensile strength, constitutive model