Abstract
Forms of sliding form method are usually made of wood except yokes, and so in many kinds of literatures and past excutions. But forms made of wood usually deform when they are used, because wood absorbs water and so changes in length. Against such deformation the use of steel sheathing boards and steel wales is effective. The excution using metal forms as sheathing boards and channel steels or angle steels as wales was success. The general difference between wood forms and steel forms can be seen in past data. But, the difference in rigidity between these and those assembled is unknown. It is important to know this because the rigidity means how much accidental load the forms can endure under construction. The rigities of assembled wood forms and assembled steel forms were tested by means of using the full sized models. Steel forms assembled with 15cm wide metal forms indicated the smallest deformation. In case steel forms are used, it need not make the top of the sheathing boards incline inside because the deformation of steel forms is small.
