94 / 2022-04-20 13:04:39

Performance Evaluation of Waste GFRP Powder/GGBS-Based Geopolymer Mortars for Rapid Repair of Concrete

Glass fiber reinforced polymer powder; Ground granulated blast furnace slag; Geopolymer; Rapid repair; Concrete

A novel method is developed for reusing the waste glass fiber-reinforced polymer (GFRP) powder and ground granulated blast furnace slag (GGBS) as precursors in geopolymer mortars for rapid repair of concrete. The effects of GFRP powder content, activator concentration, liquid to solid (L/S) ratio, activator solution modulus, and sand to binder (S/B) ratio on the physico-mechanical properties of geopolymer mortars were evaluated. Based on the 1-day compressive strength, the optimal combination of the geopolymer mortars is determined to be 20 wt.% GFRP powder content, an activator concentration of 75%, an activator solution modulus of 1.2, L/S of 0.6, and S/B of 2.0. The highest compressive strength of GFRP powder/GGBS-based geopolymer mortar is 35.7 MPa at ages of 1 day, with initial setting time of 24 min and final setting time of 29 min. The bond strength between the geopolymer mortar and concrete is 10 times higher than the bond strength between cement mortar and concrete at ages of 1 day. Microstructural analysis indicates that incorporated GFRP powder into GGBS-based geopolymers could improve the pore structure. C-S-H gel and C-A-S-H gel are formed in the GFRP powder/GGBS-based geopolymer mortars. The developed GFRP powder/GGBS-based geopolymer mortars reduce the disadvantages of GGBS geopolymer mortars and cement mortars, and thus, offer high potential as a rapid-repair material.