Discussion on The use of Lightweight Aggregates for Structural Concrete by M.E.R. Little

In his opening address to the symposium held in the Bloomsbury Centre Hotel on 5 July 1978, the then President, Mr. Peter Dunican, emphasised its objectives, which were outlined in the foreword to the published papers. Unlike other recent symposia, the purpose of the papers was to promote discussion on the stability of low-rise buildings of hybrid construction and to determine whether structural engineers desired guidance from the Institution. The subject had been considered by the Structural Codes Advisory Committee and, at their request, by the Code Servicing Panel (Convener, Mr. L. R. Creasy), and a view was now sought whether such guidance should be provided or whether it would be more appropriate to keep the matter under review. Views were also being requested through a note in The Structural Engineer (see August 1978 issue, page 233). This note has been written by the Symposium Chairman, Dr. S. C. C. Bate (Hon. Treasurer). Bound sets of the papers may be obtained from the Institution, price £5 each set post-paid (remittance with order), and a transcript of the proceedings is available, on loan from the library, to members.

The Bridge Code (BS 5400) is being prepared in ten Parts. Parts 1,2,4,7,and 8, dealing essentially with principles, loading, and concrete bridges, were published in June 1978. They have been followed by Part 5, Composite bridges (May 1979), which is the subject of this paper; Part 10, Fatigue, which includes fatigue of shear connectors is yet to be published. A brief account is given here of the drafting of Part 5, of the design studies and trial designs that have been done, and of its principal recommendations. Reference is made to its relationship with other Parts of the Code, to a Commentary on Part 5, and to the need to set up a procedure for recording experience of its use. R.P. Johnson

Use of underground space is increasing rapidly, and many young designers are becoming involved, for the first time, with subsurface tunnelled works. T.W. Hulme