Cyclic tensile behavior of carbon fabric-reinforced cementitious matrix composites

Fabric-reinforced cementitious matrix (FRCM) composites represent a valid alternative to traditional strengthening and retrofitting techniques for existing reinforced concrete (RC) and masonry structures. Recently, FRCMs have been effectively used to strengthen existing structures and as confinement of axially loaded members. However, limited research is currently available on the behavior of FRCMs under cyclic loading, which is of paramount importance for seismic retrofitting. This work experimentally investigates the tensile behavior of a carbon FRCM composite subjected to low-cycle fatigue and post-fatigue testing. Tests are performed according to the European assessment document (EAD) for FRCM composites, using a clamping-grip test setup. Either dry or epoxy-coated carbon reinforcing textiles are used. Quasi-static monotonic tensile tests are first carried out on the FRCM coupons, whose results are used to set the limits for the load-controlled fatigue tests. Two cycle sets are considered, namely 15 and 45 cycles, and the role of textile epoxy-coating is investigated. Specimens that survive cyclic testing further undergo monotonic tensile testing up to failure, to assess the post-fatigue quasi-static performance. Results shed light on how low-cycle fatigue affects the overall performance of the carbon FRCM during and after cyclic loading and highlight their potential as seismic strengthening for existing structures.