Dowel sleeves are usually made from plastic and ensure that
the dowel is debonded from the other panel.
They are usually the same shape as their dowel, but slightly wider
so that the dowel has room to move parallel to the joint, allowing for
differential shrinkage movements between the two panels.
They are usually cast in a panel before the dowel itself. If
the joint is not armoured, the temporary formwork usually has dowel-shaped
protrusions to hold the dowel sleeves in place until the concrete has set. Once
the dowel sleeve has set in place, the formwork is removed and a dowel is placed
in the sleeve. The second panel is then
cast around the exposed part of the dowel.
Dowel sleeves are also fitted to one side of the
pre-installed dowels in an armoured joint, with the steel shutter used as a