Onsite Load Testing of a System-Built Hollow-Plank Floor Assembly

Code limits on deflections On 17 November, Dr J. B. Bellamy questioned the basis for the recommended limits on deflections as set out in Codes, wondering whether perhaps the actual levels might not appear somewhat arbitrary. We have a response from Roger Mead of Brentwood in Essex: Although I support Dr Bellamy’s questioning of the rationale of deflection limits, I would raise issue with his interpretation of the limits in clause 14.7 of BS 5268. Verulam

The damage to concrete structures from expansive and disruptive alkali-silica reaction (ASR), which first became apparent in the UK in the late 1970s, necessitated the development of new inspection, testing and appraisal procedures. These were brought together in the 1988 IStructE report Structural effects of alkali-silica reaction, interim technical guidance on appraisal of existing structures. This has been substantially revised and updated in the 1992 Technical guidance to incorporate recent research and the practical experience in the use of the 1988 report. J.G.M. Wood and R.A. Johnson

Reading the viewpoint’ by E. W. H. Gifford, ‘Recollection of structural changes in the last 50 years’, prompted me to start a project I have been mulling over in my mind for several years. The project is to write an account of work in the 1950s, ’60s and perhaps the ’70s before recollections fade and the historical lessons learnt are lost in speculations of what may have happened in the past. I think it is important for future generations of engineers to have the knowledge of achievements and failures available for study to save time and effort and, perhaps, mistakes in the future. I shall start with what may be the most contentious subject, high-rise flats. T. Harley-Hadow