Mechanical behaviors of CFRP-confined sustainable geopolymeric recycled aggregate concrete under both static and cyclic compressions

Geopolymeric recycled aggregate concrete (GRAC) can greatly facilitate sustainability in the construction industry by the simultaneous utilization of solid waste-based recycled aggregate and eco-friendly binder-geopolymer. This study presents an experimental investigation on the mechanical behaviors of GRAC confined by carbon fiber-reinforced polymer (CFRP) jackets under both monotonic and cyclic compressive loading. A total of 24 CFRP-confined GRAC specimens were fabricated and tested, in which four aggregate replacement ratios (i.e., 0%, 25%, 50%, and 100%) and two thicknesses of CFRP jackets (i.e., 1 and 2 layers) were considered. The failure patterns, compressive stress-strain behavior, and axial-lateral strain responses of CFRP-confined GRAC were investigated and compared. The characteristics of stress-strain relationships were also discussed in terms of the peak stress, ultimate strain, residual modulus, plastic strain, reloading modulus, and stress deterioration ratio. Moreover, the related results were analyzed by comparing to the prediction ones of the existing models for FRP-confined concrete, to evaluate their applicability and accuracies for CFRP-confined GRAC. The outcomes will enrich the experimental database of CFRP-confined concrete and provide insights into the practical application of CFRP-confined GRAC.