Non-metallic building materials, namely, precast concrete slabs, wall forms, blocks, panels, and prestressed concrete beams, walls, floors, blocks, panels; rigid pipes, not of metal, for building; asphalt, pitch and bitumen; transportable buildings, not of metal; monuments, not of metal; prefabricated buildings, not of metal; concrete building elements, namely, precast concrete slabs, wall forms, blocks, panels, and prestressed concrete beams, walls, floors, blocks, panels