Torsional Strengthening of RC Beam using Ferrocement Jacketing

Abstract

Due to the type of loading on the structure, it is generally known that there are four structural actions: axial force, shear, bending, and torsion. The reinforced concrete beams are said to be subjected to torsion, when the point of application of lateral loads does not coincides with shear center of the beam. These loads may be due to loading pattern or connection of beam. Torsional failure is typically seen in places that are prone to earthquakes. It is considered as secondary effect of structural failure. Torsional strengthening of RC beams can be done by increasing the cross-sectional area with additional shear reinforcement, using externally bonded steel plates with Pressure grouting and other strengthening techniques like ferrocement, RC, steel, FRP, beams reinforced with GFRP and steel bars etc. In this research an experimental investigation is conducted on the improvement of torsional resistance of reinforced concrete beams using ferrocement jacketing has been attempted. For the Experimental program, three beams of each grade (M30 and M40) are taken as controlled beams and are loaded till failure and all beams are designed as torsionally deficit in middle test zone of length 300 mm and 100 mm from both ends are designed for resisting torque. Other beams have grouped in two sets loaded up to 80% and 90% loading capacity of control beam. The bearing capacity for torsional moments, the angle of twist, and the failure mechanism of the beams are analyzed and given in accordance with the effects of various configurations of ferrocement wire mesh 45° and 90° to the longitudinal axis.