Four test columns were constructed using concrete with compressive strength of 130 MPa, transverse reinforcement with yield strength of 408 or 873 MPa and ordinary longitudinal reinforcement. Those columns tested under reversed cyclic lateral loads with constant axial compressive load levels of 0.343 or 0.473. Test results indicated that even for such high strength concrete columns adequate ductility was secured by using high strength transverse reinforcement. Based on the. test results, the stress-strain model on confined concrete previously proposed by the authors was modified so as to be applicable not only to ordinary strength concrete but also to high strength concrete. It was also found that the flexural strength of such high strength concrete columns can be predicted by using ACI 318-89 stress block equation.
