Description
The cracking of the prestressed box girder bridge web is one of the difficult problems in the engineering field. The vertical prestressed loss is one of the reasons for the cracking of the box girder bridge web. Fe-SMA rebar, as a new type of prestressed material, can be used as vertical prestressed rebar in box girder bridge web to supplement the vertical prestressed loss and inhibit the cracking of web. Therefore, taking the I-shape beam with simplified concrete box girder bridge web as an example, the shear experiment of I-shape beams with Fe-SMA rebars in shear span area was carried out. The effects of Fe-SMA activation state, layout spacing and reinforcement diameter on shear performance of I-beam were studied. The variation laws of cracking load, ultimate load and main tensile strain were analyzed. The results show that the failure mode of the specimen changed from brittle shear failure to ductile flexural shear failure, and the ultimate deflection of the specimen increased significantly after the Fe-SMA rebar was activated. The activation of Fe-SMA rebar had a significant effect on reducing the main tensile stress of the section in shear span area and delaying the cracking of beam body. In addition, a method for calculating shear capacity of I-beam with Fe-SMA rebar was proposed. The calculated shear capacity was in good agreement with the experimental data, which provided reference for the subsequent research.
