An apparatus for reducing propagation of cracks in concrete includes a curved panel. The curved panel includes a convex surface and a concave surface facing away from one another and separated by a thickness. Each of the convex and concave surfaces has a top edge, a bottom edge, a first end, and a second end. Each of the convex and concave surfaces is configured to be arranged in direct contact with the concrete. The curved panel further includes a top surface extending between the top edges of the convex and concave surfaces. The top surface is substantially planar and substantially perpendicular to the convex and concave surfaces. The curved panel further includes a bottom surface extending between the bottom edges of the convex and concave surfaces. The bottom surface is substantially planar and substantially parallel to the top surface.