Retrofitting of Stressed RC Beams Using Ferrocement Jacketing

Abstract

Many existing structures located in seismic regions are inadequate based on current seismic design codes. In addition a number of major earthquakes during recent years have underscored the importance of mitigation to reduce seismic risk. Seismic retrofitting of existing structures is one of the most effective methods of reducing this risk. In recent years, a significant amount of research has been devoted to the study of various strengthening techniques to enhance the seismic performance of the existing reinforced concrete structures. Although, the seismic performance of the structures may be improved by retrofitting or rehabilitation only but the salient features of various retrofit techniques also need to be considered before selecting the retrofit schemes. Now day’s reinforced concrete structures components are found to exhibit distress, even before their service period is over due to several causes. Such unserviceable structures require immediate enquiry into the cause of distress and suitable remedial measures, so as to bring the structures back to their functional use again. Ferrocement as a retrofitting material can be pretty useful because it can be applied quickly on the surface of the damaged element without the requirement of any special bonding material and also require skilled labour as compared to other retrofitting solutions presently existing. Ferrocement is a versatile construction material and confidence in the material is building up resulting in its wider application especially in developing countries such as for housing, sanitation, agriculture, fisheries, water resources, water transportation freshwater and marine environment, biogas structure, repair and strengthening of older structures, and others. In the present work model sized the beams are casted to study the effect of change of grade of concrete and stress level on retrofitted beams. For this two different concrete grades M20 & M40 were used and are subsequently stressed to two different stress levels of 50% and 75% of the max load carrying capacity.