Acoustic emission due to fatigue damage mechanisms in high-strength concrete with different aggregates

摘要

The behaviour of high-strength concrete under compressive fatigue loading was investigated within a research project of the priority programme SPP 2020. In this paper, results concerning the influence of the type of coarse aggregate on the fatigue behaviour of high-strength concrete, with focus on the acoustic emission analysis, are presented comparatively. Two high-strength concretes with basalt and granite as coarse aggregate are investigated using two stress levels S_(c,max) = 0.85 and S_(c,max) = 0.70. Both concretes show similar characteristics of acoustic emission signals for the higher stress level. But for the lower stress level considerable differing characteristics are identified for the granite concrete. This might be an indication for a differing fatigue damage mechanism due to the type of aggregate. The damage mechanisms observed in experiments or rather the crack propagation are simulated using XFEM. Therefore, a first modelling approach is presented.