System of protecting the edges of cast-in-place concrete slab on ground, construction joints

摘要

An improved joint edge assembly, of the type used in the construction of concrete slabs, is disclosed. The assembly comprises a longitudinal joint rail, preferably of steel, which is supported off the ground by temporary formwork. The joint rail is secured to the formwork by mounting brackets. The joint rail comprises first and second joint edge members that are connected to each other by connectors with self-release elements. A plurality of studs extends downward and outward from each of the joint edge members into the concrete slabs provide a positive mechanical connection between the slab and the joint rail. As the concrete shrinks during hardening, the self-release elements of the connectors allow the joint to freely open. The joint edge assembly thus provides a self-releasing expandable joint between adjacent slab sections, and protects the edges of the adjacent slab sections from damage. A dowel aligner may also be integrated into the assembly, to allow proper positioning of dowels within the slab.