Tubbing with polymer concrete layer

The invention relates to a tubbing (1) made of concrete for lining a tunnel, in particular a tunnel for transporting corrosive liquids. The tubbing (1) has a convex-curved outer surface (2) and one of the outer surface (2) opposite the concave-curved inner surface (3). In order to form a sealing protective layer (4) on the outer surface (2) or inner surface (3) is proposed according to the invention, there provide a polymer concrete layer (4). The polymer concrete layer (4) may be additionally side surfaces connecting on the outer surface (2) and inner surface (3) (5, 6) extend to form there with circumferential seals (9) comprises a full-surface protection of the entire Tunnelinnen- or -ausenflache.