Temporal Evaluation of ASR Cracking in Concrete Specimens Using Acoustic Emission

The effect of steel reinforcement on the distribution of alkali-silica reaction (ASR) damage in concrete blocks is studied by leveraging acoustic emission sensing with a data-driven approach. The innovation lies in deriving damage contours caused by ASR based on a minimal sensor array. Through this approach, damage progression can be traced in time and event distribution can be visualized. A gap in the current literature, namely evaluating ASR progress in concrete structures with different internal restraint using acoustic emission (AE), is addressed. Unsupervised pattern recognition is utilized to study the effect of the temporal damage condition. In the confined specimen, the distribution of AE events in the midwidth region of the specimen is concentrated and close to the normal distribution. The surface cracks are mostly oriented along the specimen length and in the midwidth region. However, in the unconfined specimen, the distribution of AE events is more uniform, and cracks are randomly distributed.