Shear strengthening of reinforced concrete columns using ferrocement jacket

This paper describes the results of a research program on the strengthening, by using circular ferrocement jackets, of square reinforced concrete (RC) columns that are susceptible to shear failure. Based on 1:6 scale models, six identical RC columns were constructed. Two of these columns were tested under as-built conditions, while the remaining four were strengthened with different numbers of layers of wire mesh before being tested. Unless failure occurred at an earlier stage, all columns were tested under cyclic lateral forces and constant axial load. From the test results, it was observed that both original columns suffered shear failure at low displacement ductility. By providing circular ferrocement jackets over the entire length, however, the displacement ductility of the columns could be improved significantly. A method for strengthening the design of columns with inadequate shear strength by using circular ferrocement jackets is also proposed in this paper.