J. D. STOKLE and A. J. BELL UMIST, Manchester
The work was undertaken to investigate the extern of frame-action in structures of plain masonry walls and reinforced concrete floor slabs, when (he relative-stiffness of the slabs to the walls was varied. Tests were carried out on a single wall supporting one end of a concrete slab, the remote ends of both being pinned. A range of walls and slabs were tested to give as wide a range of relative-stiffness values as possible. Moments that developed at the slab/wall joint were measured for load applied to the slab, with and without precompression load applied to the joint. Elastic-frame action developed in all cases. Ftexural stiffnesses based on gross-section properties did not adequately predict the elastic-frame moment. The stiffness properties of the walls varied with precompression. When this was taken into account elastic-frame action could be adequately predicted. A simple edge-pivot model can be used to predict the limit to elastic-frame action, and to explain the subsequent behaviour of the slab/ wall joint beyond this limit.