Cyclic load tests on prestressed concrete model frames

Abstract Prestressed concrete frames are commonly used in bridge design. However, very little is known about their behaviour under reversed cyclic loads, particularly when subjected to severe earthquakes, and most bridge codes do not provide the required design guidelines. Results from small-scale models of eight prestressed concrete frames, tested under various load histories simulating earthquake forces are presented. The experimental primary curves (horizontal force-displacement relationships) are compared with the theoretical results, and the experimental hysteretic loops are compared with those calculated from Tadeka's rules. The concrete strength is approximately 40 MPa, and the effective prestress varied between 36% and 51% of the ultimate strength of the prestressing steel. It was found that the ductility and energy dissipation increased with decreasing effective prestress. The effect of the load history on the reversed cyclic behaviour is also significant.