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Torsional Behavior of Reinforced Concrete Elements Strengthened with Stainless Steel Wire Mesh

Many structural elements in building and bridges are subjected to significant torsional moments. The failure of reinforced concrete (RC) elements under torsional loading can be very brittle and thus, rational design of RC elements under torsion is essential.

Torsional strengthening of RC members are often carried out due to several factors. RC elements can be strengthened with the help of extra reinforcement by externally bonding a composite material. The use of fibre-reinforced polymer (FRP) composite has been widely investigated as a strengthening technique by many researchers for the strengthening of RC beams subjected to flexural, shear, axial, and torsional loading. Despite the capabilities of this system, FRP composites have several disadvantages such as  (i) difficulty to install onto a wet surface or in low temperatures, (ii) low fire resistance, (iii) low glass transition temperature, and (iv) lack of vapor permeability.

Recently, a new type of composite called Stainless Steel Wire Mesh (SSWM) is used as an alternative to FRP composites. SSWM composite comprises of a steel wire cord sheet embedded in an organic matrix (epoxy resin). SSWM offers better compatibility with the concrete substrate when compared to FRP composites. Research on the use of SSWM composite in structural strengthening applications is in its infancy. There are only a few studies exist in the technical literature on its use for the strengthening of RC members.

In the present work, small scale RC beams will be tested under torsional loading with and without SSWM strengthening. Four different wrapping configuration of SSWM will be considered in the proposed work. The torque –twist behavior, failure mode and effectiveness of strengthening techniques will be assessed based on experimental investigation. The analytical model for SSWM strengthened RC beams will be developed using Softened Membrane Model for Torsion (SSMT). Also,  nonlinear finite element analysis will be carried out to analyze the SSWM strengthened RC beams. Based on the experimental and numerical studies, design guidelines will be developed for the SSWM strengthening of RC members under torsional loading.