**5. Conclusions**

Acoustic emission was utilized for monitoring the activities caused by ASR in large-scale reinforced concrete specimens. The specimens resemble common nuclear power plant containments with no shear reinforcement. An agglomerative hierarchical algorithm was used to classify the AE data based on the energy-frequency dependent features to study and identify the damage mechanisms in the specimens with different stress boundary conditions. The conclusions of this study are summarized as follows:


**Author Contributions:** Conceptualization, P.Z., V.S., Y.L.P., and Z.J.M.; Data curation, V.S., R.A., and N.W.H.; Formal analysis, V.S.; Funding acquisition, Z.J.M., Y.L.P and P.Z.; Investigation, V.S., R.A., N.W.H. and L.A.; Project administration, Y.L.P., Z.J.M. and P.Z.; Resources, Y.L.P., Z.J.M. and P.Z.; Supervision, Y.L.P., Z.J.M. and P.Z.; Visualization, V.S.; Writing – original draft, V.S.; Writing – review & editing, V.S, N.W.H., Z.J.M., Y.L.P. and P.Z.

**Acknowledgments:** This material is based upon work partly supported by the U.S. Department of Energy, Office of Nuclear Energy, Light Water Reactor Sustainability Program, under contract number DE-AC05-00OR22725. This manuscript has been co-authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results

of federally sponsored research in accordance with the DOE Public Access Plan (https://www.energy.gov/ downloads/doe-public-access-plan).

**Conflicts of Interest:** The authors declare no conflicts of interest.
