Abstract: A crack inducer controls propagation of cracks in set concrete containing reinforcing bars. The crack inducer has an elongated, rigid core that is relatively narrow in a direction that is parallel to outer surfaces of the concrete. The core has a core width in a first plane that intersects the outer surfaces of the volume, that is at least 20% of the concrete volume width so that a crack in the volume of concrete is induced to propagate from the core and along the first plane. A plurality of spaced cross-plates are connected to the core and a water-stop may be included around part of the core.

Abstract: A crack inducer plate assembly for concrete structures having a volume and an outer surface includes an elongated and rigid core plate for extending in the volume at a location spaced from the surface, the core plate having opposite sides. A waterproof and resilient waterstop member is fixed to and covers the opposite sides of the core plate. Crossplates are welded to the core plate to anchor the core plate to reinforcing bars in the concrete. Cracks are formed in a controlled manner within the volume and by the waterstop member.