Experimental investigation on flexural behavior of a precast slab joint with perfobond strips and steel fiber-reinforced mortars

Abstract

This study aims to present a joining method for precast concrete slabs in the replacement work of the degraded concrete slab in existing steel girder bridges. The joint uses perfobond strips along with steel fiber-reinforced mortars, which is expected to be smaller and to offer a short construction time compared with traditional loop joints. Firstly, an optimized mixture of the steel fiber-reinforced mortar with both early strength development and high tensile strength is developed based on material tests. Then, eight joint specimens are fabricated and tested under flexural loads, considering the effects of various parameters associated with the layout, the perforation diameter of perfobond strips, and the curing age of joint materials. Detail discussions on load–deflection relationships, crack patterns, strain behaviors of joint components, and joint resisting mechanisms are presented. It is observed that the flexural behavior of the joint is correlated with the shear behavior of the perfobond strips, which is both significantly affected by the examined parameters. Finally, a simplified estimating method for the joint flexural capacity is then proposed according to the shear capacity of perfobond strips. The results obtained by the proposed method show a good agreement with ones from the experimental results.