19 Building materials and components, not of metal, namely, circular rings of reinforced concrete, sections of circular rings of reinforced concrete for lining tunnels of all kinds; tunnel lining segments; linings, non metallic, for building; building materials, namely, fire protection building elements, non-metallic, in the nature of circular rings of reinforced concrete, sections of circular rings of reinforced concrete for lining tunnels of all kinds, and tunnel lining segments; building materials, namely, fire protection materials, non-metallic, for use in building in the nature of circular rings of reinforced concrete, sections of circular rings of reinforced concrete for lining tunnels of all kinds, tunnel lining segments, and linings; building materials, namely, watertight linings for tunnels, not of metal, gas-tight linings for tunnels, not of metal, fire-resistant linings for tunnels, not of metal, fire-retardant linings for tunnels, not of metal