Modeling of Thermal Effects in Concrete Bridge Design

www.kstr.lth.se Thermal actions have a significant effect on bridge structures and can at some sections account for more than 20 % of the reinforcement. Such actions are especially important in certain types of concrete bridges, e.g. portal frame bridges. Thermal actions differ from other load types considered during bridge design through being a con-straining load. A temperature profile can be divided into a uniform part that affect the bridge with a linear expansion and a non-uniform part that will induce an arch shape of the bridge deck. Using the current building code, thermal actions can account for more than 20 % of the total demand of reinforcement at midsection making them so large that they cannot be neglected. This makes thermal actions in bridge design interesting for further investigation. The current building code in Sweden suggests two approaches for considering temperature differentials during bridge design. The first approach uses a linear temperature distribution through the bridge deck and the second approach uses a non-linear distribution. In this thesis, an analysis using real climate data presented by SMHI is used to determine which of the two approaches is most realistic. A simulatio