Preliminary Tests on a Shallow Unreinforced Concrete Shell

摘要

Available information on shallow thin shells with a rectangular plan is reviewed, experience with the sagging membrane casting technique is reported, and the results of tests on three models and one large shell are reported. The experimental results are compared with the membrane and the Haidukov theories. An unreinforced concrete shell 7/16 inch thick with plan dimensions of approximately 8 feet by 8 feet and a rise of 5.5 inches sustained a uniform load of 250 psf before failing in a local transitional buckling mode. One of the model shells approximately 19 inches square by 1/8 inch thick carried a uniform 'plate' load of 1,122 psf. Some information on the behavior of these shallow shells under a concentrated load was obtained. Shallow compressive membranes may be suitable for floor systems in ordinary buildings and bridges, resulting in a considerable reduction in the cost of materials and labor. (Author)