Issue 23/24

This paper describes a test programme aimed at establishing for aggregate concrete blocks the characteristic compressive strength of single leaf masonry made with voided blocks and solid blocks laid flat and also with solid blocks laid in collar jointed construction. Proposals are made for incorporating the results in the National Application Document for DD ENV 1996-1-1, Eurocode 6 and the revision to BS 5628: Part 1. It is shown that the compressive strength of blocks laid flat can be readily found from conventional compressive strength tests carried out with blocks laid on their bed face, i.e. normal aspect tests. The paper also compares the compressive strength of units prepared and conditioned by the ground/air dry method and the capped/saturated method given in prEN 772-1. M. E. Phipps, BScTech, PhD, CEng, MICE, MIStructE Professor of Structural Masonry Department of Civil and Structural Engineering, UMIST, Manchester S. A. Mirza, BSc, MSc Research Assistant, Department of Civil and Structural Engineering, UMIST, Manchester A. J. Bell, BEng, MSc, PhD Senior Lecturer, Department of Civil and Structural Engineering, UMIST, Manchester G. J. L. Pettit, Standards Manager, Tarmac Topblock M. Ormesher, Technical Manager, Forticrete N. G. Lewis, Technical Manager, RMC Concrete Products

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A primary concern in the design of reinforced concrete flat slab structures is that of punching shear at the slab-column connections. In this paper, a rational physical model for shear transfer between columns and slabs with bonded orthogonal reinforcement is described. The model predictions are compared with existing test results in the literature and with predictions based on the British Design Code BS 8110. On the basis of this model, a simple and general integrated flexural and punching shear design procedure is proposed. Numerical examples of practical design applications are given. A. A. Olonisakin, Ph.D., P.Eng. Research Fellow, Department of Civil & Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada. S. D. B. Alexander, Ph.D., P.Eng. Associate Professor, Department of Civil & Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada.