Constructions and construction elements not of metal, namely, bridges, tunnels and underpaths; constructions and construction elements of concrete, namely, beams, desks, slabs, plates and boards; modular construction elements of concrete, namely, slabs, bricks and walls; prefabricated concrete elements for the building industry and for public or private works, civil engineering and agricultural engineering, namely, prefabricated concrete walls, prefabricated concrete slabs, prefabricated conc...

precast concrete structural components, namely arch-shaped units comprising vaults and inverts, adapted for assembly to form hydraulic structures, roadway and railway overpasses and underpasses, pedestrian passageways and underground chambers, and assemblies so formed