N. A. ROUMANI and M. E. PHIPPS
University of Manchester Institute of Science and Technology
An unbonded prestressed brickwork I or T section member fails in shear after the formation of diagonal cracks in the web. When these cracks form the member may be free from ail other cracks or it may already contain cracks caused by flexure. A new method is presented for ultimate shear strength design which covers the two cases of members that are previously uncracked and members that are previously cracked due to fiexural stresses. The method is supported by experimental evidence from 22 tests which shows that the proposed method is both safe and accurate. A comparison is made with the method given in BS5628 which is shown to be based on an incorrect assumption leading to gross inaccuracy. It is also more complicated to use than the simple method proposed.