3 - Characterization of damage evolution and its influence on mechanical properties of concrete under impact loading

Abstract

The failure strength of concrete and other brittle or quasi-brittle materials has been widely observed to increase significantly when subjected to high strain-rate deformation. This observed rate dependence is believed to be largely driven by the time dependent nature of the cracking and fragmentation process. However, due to the significant technical challenges in studying this phenomenon, the underlying mechanisms driving this behavior remain mysterious. In this chapter, developments in non-destructive techniques and their application to the study of damage evolution in cementitious materials are discussed. Additionally, various approaches to interpret and extract quantitative information from the data generated by these non-destructive techniques are reviewed. With a particular focus on the study of crack initiation and propagation in concrete under high-strain rate loading conditions, in the search for a quantitative rate-dependent relation between damage evolution and the observed strength increase.