Experimental investigation on the performance of RC beams strengthened with external bars at soffit

Abstract

This paper presents the findings of the comprehensive experimental investigation on the use of non-prestressed external reinforcing bars at soffit of the RC beams for enhancing the flexural strength. Based on the encouraging results of the preliminary experimental study conducted by the authors, a comprehensive experimental investigation was carried out by testing 20 numbers of RC beams with varying internal and external bar ratio in order to further explore the viability of this technique. External reinforcing bars technique has already been used by keeping the reinforcement at the sides of the beam using deflectors, mechanical anchoring devices and with strengthening end anchorage zones. The reported technique uses external reinforcing bars at the soffit, which eliminates the need of deflectors, and the anchoring was done by adopting a very simple technique, which eliminates the use of mechanical anchoring devices. The proposed technique is found to be cost effective, easy to execute, enhances moment carrying capacity and effective in deflection and crack control.