Concrete Buckle-Shell Model Study

A method of forming latex-modified fiberglass-reinforced concrete shell roof structures with pneumatically supported foamed plastic forms is presented. Observations of the shell model during the application of the mortar indicated that on the prototype shell concrete application will have to proceed in layers and in a planned pattern of progress over the surface of the shell. The experimental and numerical elastic responses corroborated one another. In addition, the failure crack pattern reflects positions of maximum tensile strain which are presented. The ultimate load carrying capacity of the shell provides a factor of safety of about 2.5 over a design loading of 30 psf (1,440 N/m²). The shell structure could be realized either as a concrete shell or as a plastic sandwich shell as witnessed by the plastic foam form.