Studies on repair and strengthening methods of damaged reinforced concrete columns

Abstract

Jacketing method with reinforced concrete (RC), steel plates or carbon fiber (CF) sheets has been widely used to repair or strengthen the RC columns damaged by the 1995 Hyogoken-Nanbu earthquake. The purpose of experimental studies reported in this paper is to confirm those repair or strengthening effects. To investigate the shear strength and ductility of RC columns repaired or strengthened by jacketing, eight column specimens were tested under constant axial compressive load and cyclic shear forces. The main conclusions obtained from the test were summarized as follows. (1) Shear strength and ductility of the repaired columns, in which the concrete remained crushed and the longitudinal bars remained buckled, can be restored over the pre-damaged level. (2) The maximum shear strength of the column repaired or strengthened by jacketing with RC, steel plates or CF sheets can be calculated by the formulas proposed in this paper.