Abstract: An expendable article for forming the side edge of a poured in place concrete structure. The article is formed as a fabricated, elongated hollow corrugated paper box having three interconnected sides that together define in cross section a right triangular shape, including a hypotenuse side and a base side with at least two sides formed of at least two layers of corrugated paper. Vertically aligned apertures are formed in the hypotenuse and base sides for receiving therethrough a retaining stake. The form being left in place to disintergrate after a period of time.

Abstract: An arcuate end form void for providing a space between a poured concrete structure and an underlying expansive soil adjacent a round pier is formed of corrugated paper to provide temporary support of wet concrete, and conforms to the pier radius to prevent passage of wet concrete between the pier and form void.

Abstract: A form void for providing a space between a poured concrete structure and an underlying expansive soil is formed of three sheets of corrugated paper for shipping in a flat "knock-down" configuration and is erected at the construction site simply by inserting one panel into a groove between two other panels. The upper surface is comprised of three panel thicknesses, and the outer support panels are reinforced by a pair of internal support panels. The cross-sectional shape may be trapezoidal, rectangular, symmetric or non-symmetric, or have a sloped top.

Abstract: A two-part collapsible form void for providing a space between a poured concrete structure and an underlying expansive soil is formed of a foldable outer section and a foldable inner section which, when erected, is longitudinally slidable into the erected outer section. The form void may be shipped in the separated and collapsed state, reducing shipping volume by up to 85 percent, and is easily erected by hand at the job site.