Reinforced concrete members are the most abundantly used construction elements in civil engineering. These members are normally designed to sustain various types of loads. But due to several reasons the members experience much more load beyond their capacity. Inadequate attention during design and construction of new additional RCC story in our country has raised question about the performance of existing structures. RCC beam is such an important member which sometimes needs to be strengthened. There are various methods of strengthening that have been studied by the researchers such as section enlargement, use of additional bars, use of FRP and CFRP, use of ferrocement, steel plates, etc. This thesis work aims to study and compare the effect of three distinct strengthening techniques- providing additional steel bars from underneath with U shaped shear reinforcement, use of wire mesh and providing single layer of geo-textile with adhesive. The experimental results show that the percentage increase in ultimate load carrying capacity for the steel, wire mesh and geo-textile were found to be 51.96%, 26.5% and 14.5% respectively with respect to reference beams. The value of deflection at failure were 5.63mm, 6.18mm and 5.83 mm respectively while for reference beam the value was 5.33mm. The performance of geo-textile was very poor. The use of wire mesh provides greater value of deflection at failure compared to other two methods but the increase in load carrying capacity is about half of that for steel bar. The application of additional steel is labor intensive compared to other two methods but in terms of ultimate load, it overweighs the advantages compared to other two strengthening techniques.
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