An initial investigation phase of research on strengthening continuous composite bridges by posttensioning has been completed; results are summarised. The effects of various posttensioning schemes were investigated on a one-third-scale continuous three-span composite bridge model. Although various tests performed on the bridge model verified that positive and negative moment regions of continuous composite bridges could be strengthened by posttensioning, the model size prevented the testing of different tendon profile shapes and the necessary hardware. Thus, the primary objective of this research was to investigate the effectiveness of various posttensioning schemes applicable to the negative moment regions of continuous composite bridges through the testing of a full-scale laboratory model. The model was subjected to four different posttensioning tendon configurations with and without the use of strengthening angles. Data from the various tests were compared to the unstrengthened model to determine the more effective posttensioning arrangement. Data from the various tests were also used to determine the extent of composite action remaining after the concrete deck cracked.
Samenvatting