Dowels transfer load across joints in concrete. At expansion and contraction joints, dowels are used with a sleeve to allow movement.
The new Lockable Dowel from Ancon allows initial shrinkage of the concrete to take place and is then locked in position with epoxy resin, inserted from the top of the slab. The locked dowel continues to transfer vertical load, but movement can no longer take place.
This innovative product was developed by Ancon for use at temporary movement joints, most commonly constructed in post-tensioned slabs where pour size can be considerable.
It comprises a Duplex stainless-steel dowel component, a box-section sleeve with an L-shaped attachment, a locking plate and two-part epoxy resin.
The box-section sleeve allows lateral, longitudinal and some rotational movement to occur in the initial stage. The dowel is locked after a predetermined time period (generally 60-120 days), when movement between the slabs has stabilised and the joint has been filled. The grout box is topped with cementitious material to complete the installation.
The Ancon Lockable Dowel is backed by independent test results and is simple to both design and install.
In August 2008, it was selected by the UK Construction Products Association to appear in the annual publication Innovation & Achievement. It was one of only a handful of products recognised by the Association to deliver improvements in site efficiency.