Hygrothermal durability of glass and carbon fiber reinforced composites – a comparative study

Abstract This study reports the recently found critical drawback of glass fibers as compared with carbon fibers. GFRP and CFRP composites were placed into a general water bath at 80 °C until saturation for accelerated hygrothermal ageing. After ageing, the impact properties of CFRP composites improved. For GFRP composites, however, their performance under low-velocity impact degraded significantly. After removing the moisture absorbed during ageing, the strength of CFRP laminates increased to 95.75% of its original value. In contrast, GFRP composites only retained 74.65% of the strength after hygrothermal treatment. Compared with CFRP composites, GFRP composites were much more susceptible to hygrothermal attack. Tensile tests on single glass fiber were carried out which proved that both the strength and elongation-at-break decreased significantly after hygrothermal ageing. Decrease in glass fiber strength after ageing is the major mechanism responsible for the reduced performance of GFRP composites.