Results from small-scale models of eight high-strength prestressed con
crete frames, tested under various displacement histories simulating e
arthquake forces are presented. The primary curves (horizontal force-d
isplacement relationships) and the hysteretic loops are determined exp
erimentally. Concrete strength is approximately between 50 and 60 mPa,
and effective prestress is 50% of the ultimate strength of the prestr
essing steel. It is found that the effect of displacement history on t
he mechanical behavior is significant because the entire shape of the
hysteretic loops is different and the prestressed concrete frames made
of high-strength concrete with a slump of 25 cm may have al least a d
uctility factor of 8.0.