Abstract: A concrete forming device made from plastic components which can be assembled in the location of use to form a desired shape and fastened to the ground with steel stakes driven through brackets attached to components. After use, the stakes are removed and the components disassembled for use elsewhere. Desirably, the components are formed from fiberglass reinforced resins and additives of a type which impart a surface to the components of such a nature as to have little tendency to adhere to the concrete. This makes it easy to remove the components and to reuse them without cleaning. The components are constructed with suitable adaptors and couplers so that assembly can be accomplished by merely inserting male parts into female parts in a slip fit relationship. Both straight and curved shapes can be formed, as well as shapes that have both straight and curved elements.