ISSN: 2277-9655 [Singh* et al., 7(6): June, 2018] Impact Factor: 5.164 IC™ Value: 3.00 CODEN: IJESS7 http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [75] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY LEARNING OF TWISTED BEHAVIOUR OF STRENGTHEN CONCRETE Nagendra Singh *1 & Prof. Satish Parihar 2 *1&2 Rama University, Kanpur, Uttar Pradesh DOI: Will get Assigned by IJESRT Team ABSTRACT Fiber Strengthen Polymer (FRP) as an external reinforcement is used extensively to deal with the strength requirements related to flexure and shear in structural systems. But the strengthening of members subjected to torsion is explored only recently. Torsion failure is an undesirable brittle form of failure which should be avoided specially in the earthquake prone areas. In the present work, the behaviour and performance of rectangular strengthen concrete beams strengthened with externally bonded Glass Fibre Strengthen Polymer (GFRP) fabrics subjected to combined flexure and torsion is studied experimentally. Rectangular RC beams externally bonded with GFRP fabrics were tested to failure using an arrangement which transfer torque to the central part of the beam through two opposite cantilevers called moment arms. Each arm is subjected to equal static loading during the experiment. Total nine RC beams were cast and tested for the learning. All the beams were designed to fail in torsion. One of the beam was used as a control beam and eight beams were strengthened using different configurations and different types of GFRP fabrics. The learning is restricted to continuously wrapped GFRP fabrics. Experimental data on ultimate & first cracking loads, angle of twist and failure modes of each of the beams were obtained. The effect of different types and configuration of GFRP on first crack load, ultimate load carrying capacity and failure mode of the beams were investigated. The experimental results have been validated with finite element analysis by using ANSYS software and found to be in good agreement with analytical values. The experimental results show that externally bonded GFRP can increase the twisted capacity of the beam significantly. The results also indicate that the most effective configuration is the full-wrap of GFRP fabrics. In addition GFRP applied in 45 0 with axis of the beam gives more strength than GFRP applied in 90 0 with the axis I. INTRODUCTION 1.1. Overview During its whole life span, nearly all engineering structures ranging from residential buildings, an industrial building to power stations and bridges faces degradation or deteriorations. The main causes for those deteriorations are environmental effects including corrosion of steel, gradual loss of strength with ageing, variation in temperature, freeze-thaw cycles, repeated high intensity loading, contact with chemicals and saline water and exposure to ultra-violet radiations. Addition to these environmental effects earthquakes is also a major cause of deterioration of any structure. This problem needs development of successful structural retrofit technologies. So it is very important to have a check upon the continuing performance of the civil engineering infrastructures. The structural retrofit problem has two options, repair/retrofit or demolition/reconstruction. Demolition or reconstruction means complete replacement of an existing structure may not be a cost-effective solution and it is likely to become an increasing financial burden if upgrading is a viable alternative. Therefore, repair and rehabilitation of bridges, buildings, and other civil engineering structures is very often chosen over reconstruction for the damage caused due to degradation, aging, lack of maintenance, and severe earthquakes and changes in the current design requirements. Previously, the retrofitting of strengthen concrete structures, such as columns, beams and other structural elements, was done by removing and replacing the low quality or damaged concrete or/and steel reinforcements with new and stronger material. However, with the introduction of new advanced composite materials such as fiber strengthen polymer (FRP) composites, concrete members can now be easily and effectively strengthened using externally bonded FRP composites