Long-term creep behavior of novel self-anchored CFRP cable system

Carbon fiber-reinforced polymer (CFRP) cables are an attractive material for bridge cables due to their light weight, high strength, and corrosion resistance properties. However, research on their long-term creep performance is limited. In this study, long-term creep tests were conducted on self-anchored CFRP cables under various stress levels to evaluate their creep performance and residual mechanical properties. Based on experimental data, million-hour creep coefficients and relaxation coefficients were predicted. The results indicated that the self-anchored CFRP cable system had a million-hour creep coefficient ranging from 6.1 % to 7.9 % at stress levels from 0.3 f u to 0.7 f u (where f u represents the characteristic tensile strength). Additionally, maintaining low and medium stress levels for 1000 h improved the tensile strength and stability of the CFRP cables. The self-anchored CFRP system was also able to provide effective anchorage even after continuous loading. By comparing with the steel cable data in the literature, the self-anchored CFRP system exhibited smaller creep and relaxation, as well as superior residual tensile properties. These findings suggested that the self-anchored CFRP cable exhibited favorable long-term reliability, and finally self-anchored CFRP cables were successfully applied to a bridge in the campus of Tsinghua University.