CYCLIC LOADING TEST ON REAL-SCALED RC COLUMN EXTERNALLY RETROFITTED BY PC BAR PRESTRESSING

摘要

A permanent and/or an emergency seismic retrofit technique of PC bar prestressing using corner blocks for shear critical RC columns that proposed by T. Yamakawa in 1999 was verified through the cyclic loading tests on RC column specimens with a scale factor of 1/2.4. To verify the effectiveness of the proposed retrofit technique for real cases, loading tests on full-scaled column specimens were conducted under a joint-research project by the collaboration with the Center for Research on Earthquake Engineering (NCREE), Taiwan University, and University of the Ryukyus, Japan. In this paper, the experimental investigation of the full-scaled specimens and their seismic performance are compared with that of the small-scaled specimens. Experimentally it was observed that the failure mode of the full-scaled specimen retrofitted by the proposed technique shifted from shear to ductile flexural one. Moreover, by emergency retrofitting of the shear-damaged full-scaled column, the experimental lateral force capacity almost recovered with keeping the ductility and sustaining of the vertical load.