Behaviour of Exterior RC Beam Column Joint Retrofitted With HPFRCC

Abstract

Normally the RCC structures constructed these days suffers a lot of damage due to faulty construction, improper design, wear and tear, lack of proper maintenance and the frequent vibrations produced during an earthquake. During the earthquake structure becomes more & more vulnerable to collapse, for such areas the behaviour of structure is needed to be improved. The behaviour of structure is largely dependent upon the behaviour of beamcolumn joint. More attention is needed paid in reinforcing bars, their sufficient development length, proper binding and in concrete casting. To overcome the damage problems of the structure, retrofitting technique is adopted in which different components of structures are strengthened. Every retrofitting technique has its unique advantages in strengthening structural members like it may either improve strength, ductility, stiffness or any combination of these. So, depending upon the type of requirement, particular strengthening technique has to be selected. High performance fibre reinforced cement composite (HPFRCC) is one of the retrofitting concrete which is widely being developed in different countries. The application of HPFRCC in structural building has not yet gained much attention due to the lack of proper guidelines, coherent information and available literatures. So in order to have better understanding about HPFRCC in structural buildings, the dissertation work has been carried out in the beam column joint with an application of HPFRCC. The aim of dissertation is to evaluate the performance of non seismic beam column joint retrofitted with high performance fibre reinforced cement composite under quasi static reverse cyclic loading at different stress levels. The analysis of specimen performance is done at two different stress levels by carrying out its retrofitting. The results obtained in reference specimen is compared with its retrofitted specimens in terms of hysteresis curve, energy dissipation capacity, energy absorption, stiffness variation, joint stresses and joint failure analysis. It was observed that retrofitting the joint with HPFRCC improved the overall specimen performance. In addition to these hooked steel fibres has helped the specimen in regaining its original strength and in bridging the concrete from its spalling. Secant stiffness variation also displays that the retrofitted specimen helped in improving stiffness of joint.