Won Hyo Bridge, Seoul, South Korea

The 1,120 m long bridge over Han River was completed in 1981. Due to inaccurate calculations of prestressing losses and deflections caused by creep and shrinkage of concrete, additional deflections of up to 30 cm occured. These resulted in a sagging  of 5cm to 20cm at the hinges. The DSI rehabilitation concept called for external tendons, which slightly reduced deflections and strengthened the structure. The remaining sag could be eliminated by an additional asphalt layer. Twelve 19 x 0.6" DYWIDAG Tendons were applied in each cantilever and anchored in new concrete buttresses cast inside the box girders. These were connected to the concrete of the existing webs of the box girder through friction created by means of short Ø36 mm DYWIDAG Smooth Bar Tendons.