MODAL VERIFICATION OF A DESTRUCTIVE TEST OF A DAMAGED PRESTRESSED CONCRETE BEAM

A deteriorated prestressed concrete beam was removed from a bridge and scheduled for static testing, Tendons in a lower corner of the beam h ad corroded and caused the corner concrete to spall. Two of the tendon s were badly corroded and one was completely broken. Before static tes ting, a polyreference modal test was conducted. This test clearly iden tified the damaged area of the beam. Additionally, a flexibility matri x obtained from the modal test was used to predict beam behavior, It w as found that the predictions from the modal-test flexibility matrix m atched the results of the static flexural test. The modal test results were further used to create a tuned linear-elastic finite-element mod el which showed excellent correlation with both the modal and static t ests in the linear range.