Abstract
This study deals with round bar reinforced concrete columns designed according to the 1962 AIJ R/C building code. Repair and strengthening procedures and specifications of the columns damaged by earthquakes are presented and their effectiveness is experimentally confirmed. Eight column specimens were loaded to various damage states and repaired or stregthened. Shear span ratio (a/D) of two specimens is 2.0, four specimens 1.0, and two specimens 0.5. Repaired or strengthened specimens were tested again. Test results show that repair and strengthening procedures and specifications presented in this paper are quite effective. Main conclusions are following two. (1) The column damaged can be repaired using epoxy resin and epoxy resin mortar, in case of relatively light damage state. (2) The column damaged in shear failure mode can be strengthened to have much higher strength and much larger deforming capacity than those of former non-damaged column. Newly arranged hoops are quite effective especially.
