The large quantity of published information on the mechanical behaviour of concretes under multi-axial stress states has been used to formulate simple expressions that show whether structural concrete under prescribed stresses is safe according to ultimate and serviceability limit states. The report is in three parts. The first discusses in general terms the basis upon which the design criteria have been formulated. Thisis followed by a brief section that gives the recommended stress levels both for normal and lightweight aggregate concretes. The third part is concerned with graphical representation and application of these equations. There is also an Appendix which summarises the data used, includes typical stress-strain curves and justifies the simplifications made in the representation of multi-axial stress data. D.W. Hobbs, C.D. Pomeroy and J.B. Newman
The President: We have had the pleasure of listening to a most interesting paper. I am sure there is a considerable future for this line of research. I remember a few years ago being asked by Messrs. Stewart and Lloyds to advise on the possible uses of both thin walled plastic tube and very thin steel tube buried in the ground. I was not able to discover any references to research work in this field. The paper we have had before us tonight has not only given guidance with regard to the carrying capacity but has also provided interesting information about the mode of failure of the tube.
The development of dead load stresses in the columns of an eight-storey reinforced concrete structure during construction is reported. The in-situ steel and concrete stresses were measured respectively through acoustic gauges and a Carlson stress meter. Typical data on the development of steel strains are presented. The difficulties of interpreting the concrete stress meter readings are described. The influence of the construction process on the development of concrete stresses is shown. R.N. Swamy and M.M.A. Potter
Report of the Council The President When Dr. W. Eastwood, BEng, PhD, CEng, FIStructE, FICE gave his Presidential Address in October 1976, it was the fourth time in the history of the Institution that a member from Yorkshire had been installed as President. After a distinguished academic career leading to six years as Professor of Civil and Structural Engineering at Sheffield University, Dr. Eastwood in 1970 resigned that appointment to embark upon a second career as a consulting engineer.
We undertook in January to publish in our next issue a statement from the Librarian about the new classification system which has been introduced in the library and apologise that it is two issues later than was promised. However, here it now is : Since 1965 'catalogue entry slips' have been published at the back of each issue of the Journal, giving a single entry for each paper published. A UDC (Universal Decimal Classification) number has been assigned to each paper since that time (printed above the title of each paper in the text and on each 'slip'). Verulam