Performance of hemp-FRCM-strengthened beam subjected to cyclic loads

Abstract

Fabric-reinforced cementitious matrix (FRCM) composites are materials that are usually applied to strengthen existing structures. In this study, a hemp mesh coated with epoxy was manufactured and combined with a cementitious matrix to strengthen a concrete beam. This beam was subjected to bending cyclic loading tests and a nondestructive modal analysis test. The modal analysis was performed to determine the dynamic elastic properties of the beam under pre-cracking, post-cracking, and strengthened conditions. The beam stiffness increased following strengthening with hemp-FRCM. The results of the experimental cyclic loading test showed that the hemp-FRCM system improved the load-bearing capacity of the beam at the service limit state by 42%. Analytical and numerical models were adjusted and validated using the experimental results, and both proved to be effective calculation tools. The models accurately reproduced the behaviour of the FRCM-strengthened concrete beam if the strengthening connection could prevent sliding and mortar debonding failures.