Issue 17

Current methods for the design of RC walls are based on theoretical concepts and empirical expressions which do not accord with the structural behaviour of the walls in the ultimate limit state. In the present paper, recent analytical and experimental studies are used to offer supporting evidence for a constructive review of axial-flexural and shear design procedures of current Codes for RC walls. The conservative nature of the Code predicted axial-flexural strength is attributed to the underestimation of the considerable effect the small stresses may have on the loadcarrying capacity and deformational response of concrete in critical regions of a wall. Simple remedies are proposed to accurately assess the wall flexural capacity. Furthermore the review reveals that not only is the compressive zone the most significant contributor to wall resistance but also that the wall does not have to behave like a truss in order to sustain shear forces after inclined cracking has occurred. Design procedures based on the use of a physical model have been suggested to prevent the occurrence of types of failure other than flexural. The proposed revisions have been shown to result in a more economical design solution without compromising safety. I.D. Lefas

Polymer materials are commonly used in the repair of concrete structures. These polymer materials include the epoxy resins, producing polymer concrete (PC), and the acrylic/SBR modifiers, producing polymer cement concrete (PCC). In addition, other polymers are used, such as polyesters, and some non-polymer materials, such as special cements and additives. This paper concentrates on the behaviour of the epoxy resins and the acrylic/SBR modifiers, but the principles discussed apply equally to other materials. D.R. Plum

For many years, almost from its inception in fact, this Institution has supported the CEB. Originally, the support was to two distinguished Fellows - Prof. A. L. L. Baker and Dr. F. G. Thomas - who were directly involved with CEB. Later, the support was to the British National Committee of CEB in the form of an annual contribution; this situation still obtains. R.E. Rowe

Since the formation of the South Eastern Counties Branch of the Institution some 5 years ago, the writer has been involved with the Branch’s education, training and recruitment activities. During this period, the Branch has established preparation courses for the Part 3 examination. More recently, it has introduced the Institution’s interviewing procedures which are necessary to satisfy Engineering Council requirements. Professor T.J. Poskitt