Post-tensioning of reinforced concrete trough bridge decks : laboratory test

The Swedish Transport Administration (Trafikverket) is the owner of a large number of railway concrete trough bridges, which were designed according to standard codes in the 1950’s. The traffic loads are today higher than the design loads and the level of ballast is also much higher today. The degree of utilization of the bottom slab is very high, which can be confirmed by calculations and visual inspections (flexural cracks are visible). This report presents the results from a laboratory test of a trough bridge, strengthened by transversal post-tensioning of the slab, at Luleå University of Technology.Calculations according to three design codes, gives a theoretical increase of the shear capacity with 5 – 100%, and the test confirmed a large increase of shear capacity. The main objective for the strengthening was to increase the shear capacity, but also the theoretical flexural capacity was increased by 21%.Godkänd; 2012; 20130123 (jonnil