The purpose of a dowel is to prevent the lateral and vertical movement of individual concrete slabs while allowing horizontal movement for the natural expansion and contraction of the concrete. The dowel must not attach to the concrete in the same way that a reinforced steel bar bonds to the concrete. A bond-breaking material covers the dowel to prevent bonding between the dowel and the concrete.
What Are Dowel Bars for Concrete Slabs?
A dowel bar for concrete is a special type of steel bar. It is not simply a steel rod that is placed in position and then cast into the concrete slab, as that will defeat the purpose of the real dowel.