Filter Band (FB) Concrete Linings are similar to Filter Point, providing an effective and highly permeable concrete lining that resists erosive forces. Filter Band differs from Filter Point in that the form creates interconnected, tubular concrete elements that are separated by large, interwoven filtration bands. The filtration bands provide for greater reduction of uplift pressures than Filter Point Linings. Also, the biaxial alignment of the tubular elements creates two directionally determined coefficients of hydraulic friction. As a result, Filter Band achieves greater reduction of flow velocity or wave energy than Filter Point.
Filter Band concrete linings are specified in situations similar to those for which Filter Point might be specified, but which also require greater relief of uplift pressures, higher reduction of flow velocities, or greater reduction of wave run-up.