Hygrothermal ageing of UV-cured glass-fiber reinforced polymer composites in rehabilitation

In the current work, a UV curable glass fiber reinforced polymer (GFRP) wet layups were developed for rehabilitation of structures. The curing time was optimized according to the mechanical and thermal properties. As found, the resin system can be fully cured in 25 seconds for a 2 mm plate, much faster than conventional ambient temperature curing epoxy systems, which generally needs several hours to days. The glass transition temperature of the current UV cured system is about 57.5°C, while the tensile strength is comparable to the epoxy based GFRPs, indicating the feasibility of the UV curable system for strengthening structures with external bonding method. The durability performances of the GFRP in water and alkaline solutions were investigated at 20, 40 and 60°C, respectively. Weight loss of the samples immersed in water and alkaline solution was found, indicating the hydrolysis of the resin. Tensile properties of the UV cured GFRPs degraded accordingly, especially at higher temperatures. Compared to water, the ageing effect of the alkaline solution exhibits more adverse on the current UV cured GFRP composite.