| This thesis presents the results of a three phase study performed to obtain a reliable value of the bond resistance for plain reinforcing bars. In addition, the behaviour of reinforcement under ultimate load is also investigated to evaluate more accurately the flexural capacity of existing bridges.; The experimental part of this study consisted of twelve pull-out test on plain bars and a series of five flexural tests on full scale beams. All tests Were performed at the Structures laboratory of Ecole Polytechnique de Montreal. The beams have been designed according to procedures used in bridge design between 1940 and 1960, all the parameters being the same from the dimensions to the materials.; The results of the study show that the methods and assumptions used in the development length calculations were not faulty and it is possible to develop full capacity of plain reinforcing bars. The study also indicated, however, that even if the yield can be reached, it was not possible to develop stress above this limit, which cause residual over-strength and ductility problems.; Finally, the results have been compared to current code values, namely the Reinforced Concrete Building Code (CAN3 A23.3-M94) and the Canadian Bridge Building Code (CAN/CSA S688). (Abstract shortened by UMI.)... |
