One major advantage of composite bridges compared to concrete bridges is that the steel girders can carry the weight of the formwork and the wet concrete. Another advantage is the savings in construction time, which saves some money for the contractor but even more so for the road users, a fact that usually is neglected when evaluating alternative bridge designs. A further step to improve the competitiveness of composite bridges is to prefabricate not only the steel girders, but also the concrete deck. Collin will present a unique concept with dry joints between the elements, used on designing 3 bridges.
Another technique that reduces the investment as well as the maintenance costs, is integral abutments. In this case the end piers, expansion joints and bearings are excluded, and the piles are introduced in the end screens at the ends of the bridge. Measurements from a real bridge as well as laboratory tests on low cycle fatigue of the piles will be presented.

Collin will also present a method for strengthening old steel-concrete bridges by introducing composite action. The installation takes place from under the bridge, and no concrete and pavement has to be removed. Monitoring from two bridges before and after strengthening will also be presented.