The truss is formed by two adherent cables prestressed concrete elements, connected by some reinforced concrete piles. The upper part has a transversal section and a longitudinal profile, that are also a rain-water drain. The shape of the lower part permits the introduction of the prestressing reinforcement and of many types of ceiling. The top cover is realized with alluzinc slabs. The truss system is completed with the introduction of the ceiling provided with an insulating layer at the little lower beam; the interspace between the top cover and the ceiling can be used for any installation and is a natural air chamber with an effect "cold roof".
