Rehabilitation of Shear Critical Concrete Columns by Use of Rectangular Steel Jackets

This paper describes an experimental research program on the use of rectangular steel jackets for seismic retrofit of nonductile reinforced concrete frame columns with inadequate shear strength. Eleven large-scale columns were tested to examine the effectiveness of various types of steel jackets for improving the ductility and strength of columns with inadequate shear resistance. Response of the columns before and after being strengthened with steel jackets was examined. Several types of steel jackets were investigated, including rectangular solid steel jackets and partial steel jackets. The test results indicate that a thin rectangular steel jacket can be a highly effective retrofit measure for reinforced concrete columns with inadequate shear resistance.