Abstract: This invention relates to an apparatus for producing a plurality of large curved concrete building sections of uniform thickness. The apparatus includes a number of forms having a concrete core and a steel casing and being of a generally crescent shaped cross-section. The forms are aligned in face to face relationship and attached together by means of end pieces to form molds. Concrete is then introduced into the molds by a ready-mix concrete truck driving on top of the assembly. After the poured concrete has hardened the forms and end pieces are stripped from the concrete building sections.