基于库伦理论的桥面混凝土动态力学特性分析

在桥面水泥混凝土铺装层病害日益增加的背景下,为了分析在车辆动荷载作用下桥面水泥混凝土的力学性能,改善桥面铺装层使用效果,基于Coulomb理论的剪切破坏条件,通过室内试验制作圆柱水泥混凝土试块,采用SHPB试验装置对试块施加不同的冲击荷载,研究不同强度水泥混凝土试块的破坏形态、动态抗压强度和应力应变特征。结果表明：冲击荷载引起的水泥混凝土试块由块状失效破坏到粉碎状失效破坏；冲击荷载能够增强混凝土的抗压强度,对强度较低的水泥混凝土增强效果更明显,且动态抗压强度增强率最高为143.7%；在动态力学作用下水泥混凝土应力应变曲线也呈现四个阶段,随着应变的增加水泥混凝土应力应变曲线斜率变小,从应变硬化转变为应变软化特性。对水泥混凝土动荷载作用下的物理力学特征分析能为工程桥面水泥混凝土铺装层强度提高和性能改善提供一定参考价值。

Study on Dynamic Mechanical Properties of Bridge Deck Cement Concrete Based on Coulomb Theory

In the deck under the background of cement concrete pavement disease is increasing, in order to analyze the vehicle mechanics performance of asphalt concrete under dynamic loading, to improve the surfacing layer use effect and shear failure conditions, based on the theory of the Coulomb made by indoor experiment of cylindrical concrete block, using SHPB test units on test block of different impact load, The failure mode, dynamic compressive strength and stress-strain characteristics of different strength cement concrete test blocks were studied. The results show that the failure failure of cement concrete test block caused by impact load is from block failure to crushing failure. The impact load can enhance the compressive strength of concrete, especially for the cement concrete with low strength, and the dynamic compressive strength enhancement rate is up to 143.7%. Under the action of dynamic mechanics, the stress-strain curve of cement concrete also presents four stages. With the increase of strain, the slope of the stress-strain curve of cement concrete becomes smaller, and it changes from strain hardening to strain softening. The analysis of physical and mechanical characteristics of cement concrete under dynamic load can provide some reference value for the improvement of strength and performance of cement concrete pavement of engineering bridge deck.