An induced joint is created by weakening lines of the
concrete slab to ensure cracking occurs in a controlled manner. This prevents
random cracking happening throughout the rest of the slab. The design of these
joints is important to ensure the panels are spaced appropriately so further
cracks won’t then form in the middle of the panel.
Most induced joints act as restrained joints and have a
continuous span of fabric reinforcement across the joint. If designed to be a
free-movement joint, dowels are cast perpendicular to where the intended crack will
be induced, however, this is rarely seen in an industrial floor.
Most load transfer
across an induced joint is provided by aggregate interlock and the
reinforcement which crosses the joint. If the induced joint becomes a dominant
joint, it may open wide enough so that the aggregate no longer interlocks and
load transfer is only provided by the reinforcement.