Seismic Retrofit of Reinforced Concrete Columns by Fiber Sheet Wrapping without Removal of Finishing Mortar and Side Wall Concrete

Abstract

In seismic retrofit of existing buildings, there is a great demand that retrofitting work can be done while continuing operations in the building. In order not to disrupt the normal operations in the building, strict limitations on the amount of noise vibration, dust, and on the use of fire need to be adopted. Since some evaluation methods of retrofitting effects for wrapped RC independent columns with continuous fiber sheets which has an advantage in construction work were proposed, applications of this method are dramatically increasing in Japan. However, these evaluation methods can not be applied to the columns with side walls and columns with finishing mortar. When this retrofitting method is applied to these types of columns, finishing is removed and side wall concrete at the boundary portion of the columns is also removed to treat the column with side walls as an independent rectangular column. Then development of the newly effective retrofitting method is necessary to meet the above-mentioned strong demand. This paper reports the test results on retrofitting effect of RC columns with finishing mortar without removal of finishing and RC columns with side walls without removal of the side wall concrete at the boundary portion. Test results indicate the feasibility of the seismic retrofit of RC columns by fiber sheet wrapping with out removal of finishing and side wall concrete.