Authors: D. B. Callà , Y. L. Xie, G. Porco EDIZIONI SISMLAB Available online at www.sismlab.com Scientific Report Scientific Publications by Sismlab s.r.l. Spin-Off University of Calabria Rende (CS), Italy N.01 - x- 2020 ISBN: 972-12-80280-00-8 Operational modal analysis of prototype reinforced concrete structures, comparison before and after damage