Fatigue Behavior of Stirrup Free Reactive Powder Concrete Beams Prestressed with CFRP Tendons

摘要

A comprehensive study on the fatigue behavior of stirrup free reactive powder concrete (RPC) beams prestressed with carbon fiber-reinforced polymer (CFRP) tendons is presented in this paper. A total of six specimens were tested, and the effects of the shear span/depth ratio, load amplitude, and steel fiber content on the fatigue behavior of the beams were analyzed. The test results showed that the fatigue damage evolution of the RPC beams exhibiting flexural failure experienced two stages: a rapid development stage and a stable stage. In contrast, the fatigue damage of the RPC beams exhibiting shear failure developed rapidly, and the fatigue life notably decreased. It was recommended based on the test results that shear reinforcement should not be omitted from RPC beams, especially for those with a thin web where diagonal tension shear failure might occur under fatigue loading. Based on the experimental results, a method for predicting the fatigue deflection of RPC beams prestressed with CFRP tendons was proposed, and then a cumulative damage model was developed to evaluate the fatigue damage of RPC beams prestressed with CFRP tendons.