Confinement Of Concrete Elements With FRCM Composites: What Do We Know So Far?

Fiber reinforced cementitious matrix (FRCM) composites have gained popularity for strengthening of concrete structures due to their capacity to overcome some drawbacks of fiber reinforced polymer (FRP) composites, mainly related to the use of epoxy resins. Research on the topic has shown that FRCM composites can increase the axial, flexural, shear, and torsional capacity of concrete elements. However, experimental studies are still limited, and an important effort is required to develop accurate and reliable design models to predict the contribution of the system to the capacity of strengthened elements. In this paper, a quantitative review of experimental studies of axially loaded concrete elements confined with FRCM composites is presented. The influence of selected variables on the increase in axial capacity of the strengthened specimens is evaluated. Three available design models for predicting the increase in axial capacity of FRCM-strengthened concrete are assessed using a database compiled by the authors. Results show that confinement with FRCM composites can provide a significant increase in axial strength for both cylindrical and prismatic concrete specimens. Further efforts are needed to improve the performance of models to predict the axial strength and behavior of FRCM-confined concrete.