Crack propagation studies in strain hardened concrete using acoustic emission and digital image correlation investigations

Abstract

The crack formation, propagation and failure mechanism of concrete are very complex. Incorporation of fibers complicates it further, alters the damage characteristics of concrete. There is a consistent effort to impart the strain hardening properties, for which the special type of chemical fibers (Polyvinyl alcohol, PVA) is found to be very promising. Presently, an attempt has been made to understand the damage mechanisms of PVA fibers incorporated concrete (with three fibre dosages (0%, 1%, 2%) subjected to flexural loading using both contact (Acoustic Emission, AE) and noncontact (Digital Image Correlation, DIC) techniques. The advantages of AE which provides information on internal cracking and DIC which provides surface crack characteristics information are suitably exploited in this study. It was found that the combined use of both techniques has the potential to investigate the crack bridging phenomenon, to analyse the damage progression during loading, and to identify the critical failure mechanism and damage classification.

Keywords:

• Acoustic emission (AE) technique
• digital image correlation (DIC) technique
• strain hardened concrete
• damage mechanisms
• crack classification

Acknowledgements

The authors would like to acknowledge the staff of Special and Multifunctional Structures Laboratory, CSIR-SERC for their help during experiments. The authors also acknowledge Dr. Mohit Verma, Senior Scientist of Advanced Seismic Testing and Evaluation Laboratory at CSIR-Structural Engineering Research Centre for sharing the GMM MATLAB code used in the study.

Disclosure statement

No potential conflict of interest was reported by the authors.