Bond stresses in post‐installed reinforcing bars derived via fiber optic sensors

A novel application of fiber optic sensing aimed at understanding the tensile behavior of post‐installed reinforcing bars in normal‐strength concrete is presented in this paper. To comply with established assumptions of cast‐in reinforcement, such as the uniform bond stress distribution, the design bond strength of post‐installed configurations is limited. In this study, pull‐out tests in confined conditions were conducted using two high‐performance mortars. Cast‐in‐place anchorages were tested for reference. The proposed fiber optic sensors and post‐processing techniques enable to continually measure and evaluate the bond stress distribution and monitor rebar deformation. Compared to cast‐in rebars, post‐installed rebars exhibit significantly higher bond resistance, particularly due to higher bond stresses at the beginning of the embedment length. These results highlight the potential for reducing the embedment length of post‐installed rebar. Moreover, variations in stiffness and bond stress distribution are found to significantly affect the slip and rebar deformation of both cast‐in‐place and post‐installed rebar.