Precast concrete construction is being increasingly adopted worldwide including India due to a number of advantages over monolithic reinforced concrete construction. As the precast concrete buildings are being constructed, it should be capable of resisting all designed forces. Generally, precast elements are designed for axial force, shear force and bending moment. But torsional force cannot be neglected in precast construction. Connections are a critical part of any precast structure. It is also observed that the failure of the precast building took place because of connection failure. Therefore it is important to study the behavior of precast connections under the effect of pure torsional loading.
A number of strengthening and rehabilitation techniques for a variety of structural elements have been proposed and studied. However, strengthening of precast reinforced concrete elements when subjected to torsion is not explored in detail. Therefore, the present study is to evaluate torque and twist behavior of precast wet connections strengthened using different wrapping configuration of SSWM. Total of 40 beams will be prepared with M25 grade of concrete. All the beam specimens will be having the cross-section dimension of 150 mm x 150 mm with a length of 1300 mm. Beams are reinforced with 4 – 10 mm diameter longitudinal bars in four corners and closed stirrups in the transverse direction with 8 mm diameter bars at 150 mm center to center spacing. A clear cover of 20 mm to longitudinal reinforcement is provided for all the beams.
Four different wrapping configurations of SSWM and three different wet connections are adopted for the present experimental work. The study is focused on the effect of SSWM wrapping configuration and wet connections on torsional strength, torsional moment – twist per unit length response and the mode of failure. For validation, a numerical investigation is carried out using finite element (FE) based ABAQUS software. The present study offers SSWM as an economical alternative of FRP to researcher and professionals for a torsional strengthening of precast reinforced concrete elements.