Puente sobre el río Miño en la autovía-VI, Lugo. Galicia

River Miño bridge, A-6 highway, Lugo, Galicia

This paper describes the bridge over River Mino in Lugo, in the 26 highway from Madrid to La Coruna. The double lane deck is 271 m length and 13 m width, and has seven inner spans of 32 m each. The deck is prestressed concrete, constructed from precast segments mounted span by span on launching girder. The transversal section design optimizes lightenings because these are reusable formwork. The segments, once precasted in a yard, are brought on trucks to the work site and, with a crane, positioned by small cars on the launching girder. Once all the segments in a span are placed and concrete is poured for the closing segment, final prestressing is applied and the launching girder is self-carried (supported) to next position. On the second part the bridges piers are described, 1.20 circunferential diametre, and capital topped to support the deck double bearing. Piers are made of 65 N/mm² concrete, obtained by the addition of silicilia fume. Relation between pier diametre and compression strength is studied in order to estimate the right pier measurement. The use of high performance concrete in elements subdued to a very high compression strength is a cheaper alternative comparing with the use of convetional concrete.