Patent ID: 7637689

Claim:
An on-grade joint-stability system for substantially restricting relative vertical movement of on-grade concrete-slab portions that meet at a joint that does not require load transfer, the system comprising: a first on-grade concrete-slab portion; a second on-grade concrete-slab portion that meets the first on-grade concrete-slab portion at the joint; multiple, separate first on-grade plates each having a first portion and a second portion, the first portion of each first on-grade plate being positioned underneath, and connected to, in opposition to vertical separation from, the first concrete-slab portion, and the second portion of each first on-grade plate being positioned underneath the second concrete-slab portion; and multiple, separate second on-grade plates each having a first portion and a second portion, the first portion of each second on-grade plate being positioned underneath the first concrete-slab portion, and the second portion of each second on-grade plate being positioned underneath, and connected to, in opposition to vertical separation from, the second concrete-slab portion; the first and second on-grade plates having portions, positions and connections as described such that through such portions, positions and connections the first and second on-grade plates substantially restrict relative vertical movement of the first and second on-grade concrete-slab portions that would otherwise result in a height differential across the joint between the first and second on-grade concrete-slab portions; wherein a substantial quantity of the first and second on-grade plates are tapered such that such plates each have a relatively wider end and a relatively narrower end, and adjacent the joint, have a portion with a gradually decreasing width.