A series of tensile strength tests were carried out to investigate the effects of long-term sustained loading on carbon fiber reinforced thermoplastic (CFRTP) stranded rods under environmental conditions. The objective was to obtain fundamental data for durability assessment. Specimens were extracted from both in-service structure reinforced with carbon fiber strands and newly manufactured strands. To assess the influence of aging on mechanical properties - specifically tensile strength and stiffness, a comprehensive experimental program was implemented, combining tests on as-manufactured strands with those on field-extracted specimens. The results provide quantitative insights into the time-dependent degradation of mechanical performance relative to the original condition.
Fujita et al. (Thu,) studied this question.