Effect of endogenous deformations in composite bridges

Early age endogenous deformations due to concrete hydration heat, shrinkage and creep can represent a real cracking risk for composite bridge beams. The phenomenon is very complex and difficult to be taken into ac-count by designers of composite bridges, as it takes place when material properties of concrete are quickly changing in time. Recommendations on this topic in design codes and literature are generally scarce and some-times ambiguous; for instance, EN 1994-2 and SETRA Guidance book Eurocodes 3 and 4 give contradicting indications. The aim of this work is to perform three sets of non-linear thermo-mechanical analyses on three different bridges: a simply supported one with two-beam girder (50m span) and two continuous ones, the first with two-beam girder (40+50+40m spans), and the second with orthotropic box shaped section (60+80+60m spans). The analyses will show the differences between the bridge typologies and will help to understand the relevance of the hyperstatic behaviour in continuous beams.