Effects of pretension loads on bending behaviors of CFRP tendons

Carbon fiber reinforced polymer (CFRP) tendons have a high potential to replace steel ones in bridge structures. However, concerns have been raised about their poor transverse properties, particularly when CFRP tendons experience combined tensile and bending loads, as in externally pre-stressed structures. This paper aims to understand and predict the bending behaviors of CFRP tendons with a pretension load. The experiment investigated the static bending behaviors of the CFRP tendon with pretension ratios ranging from 0 to 0.6. The pretension load stiffens the bending behavior of CFRP tendons, and a lower pretension ratio leads to an obvious increase in both the maximum bending load and energy dissipation. An analytical model was proposed to predict the load-deflection relationship and threshold pretension ratio of CFRP tendons under combined tensile and bending loads. The proposed model is in good agreement with the experimental results.