混凝土在持续高拉应力作用下的破坏

Failure of concrete under sustained high tensile stress

本文用10×10×55cm轴拉试件,进行了持续高拉应力作用下混凝土破坏规律的研究,得到了应力水平与持荷破坏时间的关系,进而评估了混凝土的使用寿命。本研究还应用超声脉冲检测技术,探讨了混凝土内部结构变化规律。结果表明,拉伸过程中混凝土内部结构存在2个不连续点,它们分别与持续高技应力下的持久强度和徐变破坏极限较好地吻合。

By using 10×10×55cm uniaxial tensile specimens, the failure of concrete under sustained high tensile stress is investigated experimentally. The relation between the specific stress and the failure time of concrete under sustained tension is obtained, from which the lifetime of concrete is appraised. Meanwhile the authors used the technique of ultrasonic pulse to investigate the mode of change of interior structure with time. Test results show that two discontinuity points could be found in tensile stress-amplitude attenuation curve, they correspond to long time strength and creep failure limit respectively.