Water absorption and hygrothermal ageing of ultraviolet cured glass-fiber reinforced acrylate composites

In this article, an ultraviolet curable glass fiber reinforced polymer (UV-GFRP) composite developed for fast repair or strengthening of concrete structures, was investigated on its water absorption and hygrothermal ageing behaviors. Cured UV-GFRP coupons were subjected to immersion in distilled water or concrete pore solution (pH value around 13) for 48 months at room temperature and elevated temperatures (40 and 60 degrees C), respectively. Water absorption and thermomechanical properties of the samples were tested as a function of immersion time. Water uptake curves of UV-GFRP exposed to elevated temperatures and/or alkaline solutions show serious mass loss. Debonding of fibers from resin matrix brought in increased coefficient of diffusion along fiber directions, due to the capillary effect. After 4 months of immersion in both media, the tensile strength of UV-GFRP was deteriorated remarkably, while the tensile modulus was less affected. According to Arrhenius equation, the tensile strength of UV-GFRP is predicted to remain 77.6% of its original value after50 years when immersed in water at 20 degrees C, but only 24.5% left in the case of alkaline solution. This suggests that the present UV-GFRP system does not suit for the application in strong alkaline environments. POLYM. COMPOS., 2012. (C) 2012 Society of Plastics Engineers