Shake table tests on prestressed concrete frames

Results from small scale models of prestressed concrete frames, tested by a shake table simulating earthquake forces are presented. The primary curves (horizontal force-displacement relationships) and the hysteretic loops are determined experimentally. Concrete strength is approximately between 32 and 84 MPa, and two types of effective prestresses are used, namely, 40 and 80 percent of the yielding stress of the prestressing bars. It is found that the effects of concrete strength and effective prestress on the ductility are significant because the ductility increases with increasing concrete strength and with decreasing effective prestress, and the prestressed concrete frames may have at least a ductility factor of 8.0.