A requirement for heavier vehicular transport on the Norwegian road network has resulted in a demand forincreased bearing capacity for many of the older bridges in the country. Many of the bridges that have beenfound to have insufficient capacity against present-day demands are steel girder bridges with concrete slabswithout a shear connection between steel and concrete. There is a large number of bridges of this type inNorway and the paper presents strengthening of two of those, in Aust-Agder county in the south of thecountry. These bridges are approximately 30 m long, single span. The bearing capacity has been upgraded byinstalling composite action between the steel girders and the concrete slab using coiled pins, in conjunctionwith thickening of the bottom flange of the steel girders. To obtain composite action, the pins are fitted totightly drilled holes through the top flange of girders up into the concrete slab. Coiled pins have not been usedmuch for bridge applications. In the work presented, the method has been found to have advantages in termsof cost and workability. Furthermore, the method has benefits when viewed from an environmentalstandpoint, since it allows strengthening