Presidential Address

The Chairman (Professor H.J. COLLINS, M.Sc., M.I.C.E., M.I.Struct.E., M.I.Mech.E., President of the Institution of Structural Engineers), welcoming the members of the Royal Institute of British Architects, said there were too few occasions on which architects and engineers got together to discuss problems of mutual interest. Defining “discussion” as “a means of arriving at conclusions which will be beneficial to the individual who doesn’t know,” he said that collaboration between the two professions was of inestimable benefit to the nation as a whole and that if the people on whom the future of this country depended decided to differ, it would be disastrous to those people who were unable to help themselves and were dependent on them.

Many investigators have published test results concerning the maximum strain capacity or extensibility of concrete in tension since Considere first stated his hypothesis that the extensibility of reinforced concrete was ten to twenty times greater than that of unreinforced or plain concrete; A resume of these early experiments on the cracking of concrete is given in a comprehensive paper by Dr. F.G. Thomas2, from which it is clear that the majority of workers strongly disagreed with Considere’s findings in that the strain capacity of reinforced concrete is approximately the same as that of plain concrete. Professor R.H. Evans