Dynamic behaviour of frames containing prestressed concrete beams

Results from small scale models of frames containing prestressed concrete beams, tested by a shake table simulating earthquake forces, are presented. The dynamic response analysis of such frames are described. A comparison between tests and analysis is made. Basically, there are three parameters in the test programme, namely concrete strength, effective prestress and seismogram. Concrete strength is approximately between 32 and 84 MPa. Two types of effective prestresses are used: 40 and 80% of the yielding stress of the pretressing bars. Two kinds of seismogram are used: 1940 EL Centro acceleration and linear incremental acceleration. 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. Also, linear incremental seismogram produces smaller ductility.