Markus Vill

Assessment of Damaged Post-Tensioning Tendons

The actual condition and the durability of post-tensioning tendons in bridges built in the early years of prestressing are often questioned, as the ultimate strength of a bridge over its lifetime is not a constant but decreases with time due to different sources, mainly due to degradation of the post-tensioning materials. Many countries face the problem that some of their post-tensioned bridges have to be demolished because concerns regarding their ultimate strength are raised. Thus, the realistic assessment of existing structures of the ageing bridge stock within the national road and railway network is of enormous economic importance. In order to assess the influence of damaged tendons of a post-tensioning system on the ultimate strength of existing bridges more accurately, a series of tensile tests on damaged tendons, which were built using post-tensioning strands and wires from demolished bridges, was carried out.