AE法を適用したコンクリートの劣化度評価に関する実験的研究(Part2) : 繰返し載荷および加熱によって劣化したコンクリート

Abstract

In this study, the acoustic emission method was applied to the damage evaluation of concrete subjected to cyclic loading and heating. Following results were obtained in this study : 1) In the case of concrete damaged at an early age, the AE activity is hardly affected by the damage, because the reaction of hydration proceeds sufficiently after damaged and then the micro crack disappears. Accordingly, it is necessary to choose the concrete damaged at the age having sufficient hydration, so as to predict exactly the concrete damage by the AE method. 2) The damage valuation of mortar damaged by heating can be estimated by the accumulative AE events measured until maximum load, but that of concrete is very difficult, because the AE activity is also affected by the coarse aggregate. 3) In the case of specimen tested immediately after damaged, it is difficult to evaluate exactly the deterioration of the concrete, because the AE activity is also affected by Kaiser effect. The deterioration of concrete aged moderately from the initial loading can be evaluated accurately by using the amplitude distributions measured at each stress level.