ABSTRACT
The strength and ductility of concrete were enhanced by the confining pressure from lateral hoops and steel sections based on earlier research works. According to Mirza and Skrabek, concrete in steel reinforced concrete (SRC) columns can be divided into three regions: the unconfined concrete region, partially confined concrete (PCC) region within the hoops, and highly confined concrete (HCC) region between the flanges of the steel section. The modified confinement model for SRC columns can be developed by combining the verified PCC model and the HCC model. For highly confined concrete, an analytical model was proposed by Chen and Lin to predict the behavior of SRC columns. The lateral confining pressure depends on the strength and volume ratio of the transverse reinforcements, layout of reinforcing steel, and confined concrete area. Modified confinement models for SRC columns were defined by combining the confinement model for PCC and the confinement effect from the steel section.
