Quantitative evaluation and visualization of cracking process in reinforced concrete by a moment tensor analysis of acoustic emission

Two types of reinforced concrete specimens under cyclic loadings have been subjected to fracture tests. In order to quantitatively evaluate and visualize the cracking process, a moment tensor analysis is applied to the AE waveforms detected during the fracture. For purposes of comparison, previous result from an engineering structure is also considered. In general, all these results demonstrate a great promise of the analysis for quantitative evaluation and visualization of the cracking process in reinforced concrete. By studying the relationship between the opening width of surface cracks and the Kaisser effect, it has been found that the breakdown of the Kaiser effect and high AE activities during unloading can be effective indices to estimate the level of deterioration in concrete structures.