An experimental study on loading rate effect on acoustic emission based b-values related to reinforced concrete fracture
An experimental study on loading rate effect on acoustic emission based b-values related to reinforced concrete fracture
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DOI：
10.1016/j.conbuildmat.2014.07.076
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发表时间：
2014-11
影响因子：
7.4
通讯作者：
R. Sagar;M. M. Rao-M.
中科院分区：
文献类型：
--
作者：
R. Sagar;M. M. Rao-M.
本文报道了用声发射技术分析钢筋混凝土梁的断裂过程。重点研究了加载速率对钢筋混凝土结构裂缝发展过程中基于声发射的b值变化的影响。对3.2m长的钢筋混凝土梁进行了4 kN/S、5 kN/S和6 kN/S的荷载控制试验，并用地震学中的b值分析方法研究了钢筋混凝土结构的破坏过程。此外，b值还与钢中的应变有关，以评估损伤状态。当加载速率较高时，裂纹的快速发展导致b值的快速波动和下降。此外，还观察到混凝土在较高的加载速率(或较高的应变速率)下表现出相对较高的脆性。在低加载速率(或低应变率)下发生少量但幅度较大的声发射事件时，平均b值较低，而低幅度声发射事件的数目较多。
This article reports on analysis of fracture processes in reinforced concrete (RC) beams with acoustic emission (AE) technique. An emphasis was given to study the effect of loading rate on variation in AE basedb-values with the development of cracks in RC structures. RC beams of length 3.2 m were tested under load control at a rate of 4 kN/s, 5 kN/s and 6 kN/s and theb-value analysis available in seismology was used to study the fracture process in RC structures. Moreover, theb-value is related to the strain in steel to assess the damage state. It is observed that when the loading rate is higher, quick cracking development lead to rapid fluctuations and drops in theb-values. Also it is observed that concrete behaves relatively more brittle at higher loading rates (or at higher strain rates). The averageb-values are lower as a few but larger amplitudes of AE events occur in contrast to more number of low amplitude AE events occur at low loading rates (or at low strain rates).