Development of stiffness and ultrasonic pulse velocity of fatigue loaded concrete
Development of stiffness and ultrasonic pulse velocity of fatigue loaded concrete
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DOI：
10.1002/suco.201600007
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发表时间：
2016-12-01
影响因子：
3.2
通讯作者：
Marx, Steffen
中科院分区：
文献类型：
--
作者：
von der Haar, Christoph;Marx, Steffen
疲劳荷载混凝土结构的损坏过程取决于所施加的荷载循环的数量和幅度。损伤的演变与混凝土刚度的降低有关，人们认为这种降低会导致构件层面的应力重新分布，这对结构的使用寿命产生有利的影响。到目前为止，刚度降低和应力重新分布从未在实验室测试或现场成功测量。只知道实际使用寿命比计算寿命长，并且刚度降低指标（例如部件挠度）随着施加的负载循环次数而增加。超声波测量技术被认为非常适合检测循环负载引起的退化过程。预计可以通过超声波脉冲速度测量可靠地记录疲劳加载混凝土结构的刚度降低。鉴于此，对小型混凝土试件进行了疲劳试验。测试的目的是了解观察到的样本刚度退化与超声波脉冲速度测量结果之间的相关性，并估计在连续结构健康监测中使用超声波脉冲速度测量的潜力。
Damage processes in fatigue loaded concrete structures depend on the number and amplitude of the load cycles applied. Damage evolution is linked to a reduction in concrete stiffness, and it is thought that this reduction causes stress redistributions at component level which have a favourable impact on the service life of a structure. Until now, the stiffness reduction and stress redistribution have never been successfully measured in laboratory tests or in situ. It is only known that the real service life is longer than the calculated one and that indicators of stiffness reduction, such as component deflection, increase with the number of load cycles applied.Ultrasonic measurement techniques are considered to be well suited to detecting degradation processes caused by cyclic loading. It is expected that the stiffness reduction in fatigue loaded concrete structures can be recorded reliably with ultrasonic pulse velocity measurements. In the light of this, fatigue tests were performed on small-scale concrete specimens. The aims of the tests were to understand the correlation between the observed stiffness degradation of the specimens and the results of ultrasonic pulse velocity measurements and to estimate the potential for using ultrasonic pulse velocity measurements in continuous structural health monitoring.