Predictive Capability of Existing Confinement Models for FRCM Composites Confined Concrete

Concrete confinement by the means of external fiber reinforced polymer (FRP) jacketing has been proved to be an effective method to increase the compressive strength and ductility, as well as mitigating deterioration due to aging, chemical attacks, overloading, and seismic activity. Concerns about the organic matrices used in FRP resulted in the development of fiber-reinforced cementitious mortar (FRCM) as a cost-effective and sustainable alternative system, used to repair reinforced concrete beams in shear and flexure, or in column confinement. Several theoretical models have been proposed for FRCM confined concrete elements, based on limited laboratory tests. In this study, the predictive capability of four design models has been tested by comparing their predictions for confined concrete compressive strength (fcc) and ultimate axial strain (εcc) with a large experimental database of 137 samples found in the literature. The model developed by Ombres and Mazzuca [6] provided the highest calibrations with test data, although it still needs further improvements to include the effects of key geometric and material variables. Further efforts should be made to improve the performance of the design models and provide an accurate theoretical confinement model for FRCM-wrapped columns, for design and evaluation purposes.