Fracture analysis of typical construction materials in natural time

Abstract The acoustic emissions observed before the failure of typical construction materials like marble and cement mortar are analysed in natural time. The study of the variance κ 1 of natural time, the entropy S , as well as the entropy S − under time reversal reveals the presence of two behaviours which can be understood either by the Burridge–Knopoff (BK) train model or the Olami–Feder–Christensen (OFC) earthquake model. The present results may be of practical importance for the identification of the time of failure of materials subjected to increasing stress.