Cracks have a serious impact on the safety of concrete structures, and the tensile behavior of concrete is the key to control generation and propagation of crack. To improve the safety of concrete structures, it is crucial to understand the mechanical properties of cracked concrete under uniaxial tensile load. In this article, dynamic tensile test and tensile test after different fatigue damage were conducted to investigate the mechanical properties of cracked concrete. First, the damage evolution law of cracked concrete under dynamic tensile load was investigated by means of d CMOD ( d CMOD : crack mouth opening displacement) control mode whereupon the relationship of stress–dCMOD considering rates effect was obtained. Then, the change law of cracked concrete under uniaxial tensile load after fatigue damage was studied by analyzing four mechanical parameters including tensile strength, elastic modulus, critical displacement, and fracture toughness. The empirical formulas of the four parameters with numbers of fatigue cycles are given. Furthermore, acoustic emission technology was applied additionally.

中文翻译：

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单轴拉伸荷载作用下开裂混凝土的力学性能

裂缝严重影响混凝土结构的安全，混凝土的抗拉行为是控制裂缝产生和扩展的关键。为了提高混凝土结构的安全性，了解开裂混凝土在单轴拉伸载荷下的力学性能至关重要。本文通过动态拉伸试验和不同疲劳损伤后的拉伸试验研究开裂混凝土的力学性能。首先，通过d CMOD（d CMOD：裂纹口张开位移）控制模式研究了动态拉伸荷载作用下开裂混凝土的损伤演化规律，得到了考虑速率效应的应力-dCMOD关系。然后，通过分析抗拉强度、弹性模量、临界位移和断裂韧度四个力学参数，研究了疲劳损伤后单轴拉伸荷载作用下开裂混凝土的变化规律。给出了四个参数与疲劳循环次数的经验公式。此外，还额外应用了声发射技术。