Comparisons of flexural properties of GFRP under accelerated exposure test with ones under outdoor test

摘要

The present paper discusses comparisons of flexural properties of GFRP under accelerated exposure test with ones under outdoor test. One of the specimens is made of glass fiber chopped strand (GFRP) mat and another specimen is made of the same unsaturated polyester resin as the matrix of the GFRP mat. In order to clarify the effects of both exposure periods on the variation of flexural strength and modulus, matrix volume fraction, thickness and absorption rates of infrared rays, a complex accelerated exposure test was conducted to continue for up 20 cycles and a direct outdoor exposure has been also conducted to continue for 4 years. It is shown that both weatherability flexural strengths decrease with the periods of exposures and the decreasing rate of unsaturated polyester resin is larger than one of GFRP mat. From the experimental results of both exposures, it is clear that one year outdoor exposure test corresponds to about 5 cycles of the accelerated test according to the flexural strength. It is also shown that both weatherability flexural strengths can be calculated by the results of the polyester resin and thickness change of GFRP during the exposures.