Correspondence on The Stress Limits For Reinforced Concrete in BS 5400 by P.A. Jackson

Mr Wex: I thought there was a degree of contradiction between David Quinion and Geoffrey Hutton. I inferred David Quinion was implying that, with quality assurance applied to innovation, there really was very little that the innovator could not prove before the structure was constructed. I think that Geoffrey Hutton is saying-and I rather agree with him-that if we do a reasonable amount of laboratory testing (or, perhaps, however much we do), it is not until the structure has been up for 10, 20, 30, or 40 years that we really find out what is happening to that innovation because of the difficulty of reproducing in laboratory short-term experiments long term environmental conditions. I am misunderstanding you both?

Professor R. P. Johnson (F) (University of Warwick): It is instructive to compare the results of these 24 tests with the conclusions from 16 tests on plated beams reported in 1981, which were less encouraging than those now reported. There are no inconsistencies, but some questions remain. The relevant conclusions were as follows.

In his Presidential Address Keith White reiterated the concerns expressed earlier in the year of the effects of fee competition on the profession. He goes on to say that many smaller practices may be ineed of help on this issue, among others. C. Mitchell