EXPERIMENTAL INVESTIGATIONS OF RC COLUMNS WITH EXTREMELY LOW-STRENGTH CONCRETE CONFINED BY HIGH-STRENGTH STEEL BAR PRESTRESSING AND STEEL PLATE

An important aspect of the proposed retrofit technique is that initial prestressing can be introduced into RC columns through PC bars (high-strength steel bars) with the help of corner blocks, and thus the benefits of active and passive confinement as well as shear reinforcement can be captured. To investigate and utilize these aspects completely, cyclic loading tests and axial compression tests were conducted on RC columns with extremely low-strength concrete (cylinder strength of concrete = 3.3MPa) confined by PC bar prestressing and steel plates. Consequently, the experimental lateral force capacity of retrofitted specimens increased to about 3 times of the capacity of the non-retrofitted specimen, and the ductility was greatly improved. In axial compression tests, the axial compression force of retrofitted specimens increased to about 3.7 times of that of the non-retrofitted specimen

Keywords:

Active Confinement , Seismic Retrofit , Extremely Low-Strength Concrete