In an earlier form, an articulated, predominantly concrete mat is disclosed in U.S. Pat. No. 5,108,222, the disclosure of which is incorporated by reference herein. In an improved form, an articulated, predominantly concrete mat is disclosed in U.S. Pat. No. 6,612,776 B1, the disclosure of which is incorporated by reference herein. As disclosed in these patents, such a mat has numerous uses in retarding earth erosion due to wind, water, or both and in lining a driveway, a parking area, or an emergency roadway.
U.S. Pat. No. 6,612,776 B1 discloses that the articulated, predominantly concrete mat comprises concrete blocks, which are connected to one another by flexible members of a flexible geogrid. As disclosed therein, the articulated, predominantly concrete mat is made from a concrete slab, in which the flexible geogrid is embedded. As disclosed therein, the concrete slab has relatively thicker portions, which define such blocks, and relatively thinner portions, along which the concrete slab is broken to form such blocks and which has holes to facilitate breaking of the concrete slab. As disclosed therein, the flexible members of the flexible geogrid are flexible straps, as disclosed in U.S. Pat. No. 5,108,222, or are flexible strands or strand bundles.
Typically, an articulated, predominantly concrete mat, as discussed above, is sized to cover a ground area very many times smaller than a flexible geogrid, as available commercially, is able to cover. Thus, before being employed in an articulated, predominantly concrete mat, as discussed above, the flexible geogrid must be first cut to a smaller size. In a flexible geogrid, as available commercially, if spacings between the flexible members are imprecise in a longitudinal direction, in a lateral direction, or in both directions, it is difficult to employ the flexible geogrid in an articulated, predominantly concrete mat, as discussed above.
Moreover, in an articulated, predominantly concrete mat, the flexible members of the flexible geogrid reinforce the concrete blocks, except that the concrete blocks along the longitudinal and lateral edges of the articulated predominantly concrete mat may not be sufficiently reinforced by the flexible members of the flexible geogrid to prevent outer corners of the concrete blocks from cracking or breaking.
Furthermore, when a flexible geogrid, as available commercially, is embedded in a concrete slab, which is cast from a concrete slurry, the flexible geogrid tends to float upwardly in the concrete slurry, before the concrete mat has cured.
For any one or more of the foregoing reasons, a flexible geogrid, as available commercially, may prove to present shortcomings disfavoring its use in an articulated, predominantly concrete mat, as discussed above.