Circular formwork

摘要

Disclosed is a formwork element ( 1 ) which can be assembled with other formwork elements ( 1 ) so as to form a formwork structure. A formwork shell ( 4 ) having an adjustable curvature is supported by means of back supports ( 5 ) so as to create a stiff formwork element ( 1 ) that sustains concreting pressure. The supports ( 5 ) have a preferably trapezoidal cross section and are provided with fastening flanges ( 6 ) on the edges thereof and at least one girder ( 7 ) that is located at a distance from the formwork shell ( 4 ). The length of the girder ( 7 ) is adjustable in order to set or modify the curvature of the formwork shell ( 4 ) which is mare of steel or plastic. Intermediate pieces ( 9 ) are disposed between the fastening flanges ( 6 ) of the supports ( 5 ) and the formwork shell ( 4 ). The fastening flanges ( 6 ) are fixed to said intermediate pieces ( 9 ) so as to be pivotable or tiltable relative thereto about the longitudinal direction thereof. The cross section of the flanges and/or the intermediate pieces ( 9,12 ) having a convex shape or being provided with slopes ( 61 ).