Rehabilitation of RC columns using ferrocement jacketing

An experimental investigation on the effectiveness of ferrocement jacketing for rehabilitation of square and rectangular RC columns preloaded with a fraction of its ultimate load carrying capacity has been carried out. The corners of the columns were rounded for improving the effectiveness of confinement. The primary variables considered were number of layers of ferrocement mesh and amount of preloading. The study was carried out on square and rectangular RC columns of similar cross sectional area and reinforcement. Total of 20 columns were tested which were grouped as A and B with a cross- sectional aspect ratio of 1 and 1.5 respectively. Each group included two control columns without jacketing and eight rehabilitated columns with two and three layers of wrapping. The corners were rounded at a radius of 37.5 mm. Columns except control specimens were preloaded up to 70% and 100% of its ultimate load carrying capacity. It was observed that, the confinement effectiveness and hence load carrying capacity of columns improved with number of layers of wrapping but reduced with increase in aspect ratio and preloading rates. An analytical model is also proposed to predict the ultimate load carrying capacity of columns after rehabilitation.