Patent attributes
A flexible, molded, polymeric grid is embedded in a predominantly concrete mat comprising a concrete slab having relatively thicker portions defining blocks connected by relatively thinner portions, along which the concrete slab is breakable. The flexible grid has two longitudinal edges, two transverse edges, longitudinally extending members, and transversely extending members, where the longitudinally and transversely extending members connect the blocks to one another when the concrete slab is broken along the relatively thinner portions. The longitudinally and transversely extending members meet at nodes, which are spaced uniformly from one another, both longitudinally and transversely, except that, along the longitudinal and transverse edges, each node is spaced more distantly from the nodes nearest to the node. When the longitudinal and transverse members are disposed in an imaginary plane and the flexible grid is not stressed, fingers, which are unitary with the grid, extend from the imaginary plane.