Structural Design of Century Tower, Tokyo

Preservation of structural timbers On 19 May, we summarised the background to the correspondence that has appeared in Verulam on this topic. Dr A. F. Bravery, who is Head of Timber Division at BRE, enlarges on the numerous factors affecting the issues covered by our correspondents: In focusing on the specific issue of achieving adequate penetration of liquid wood preservatives into the heartwood of timber species that are inherently variable or inconsistent in their resistance to fluid penetration, and on whether specification and monitoring should be on a results or process basis, your correspondents appear to cast doubts on the confidence in timber in general and preservative-treated timber in particular for structural purposes. This is particularly regrettable at a time when the supreme environmental advantages of wood as a natural, renewable material, which absorbs carbon dioxide from the atmosphere, have never been more important. Verulam

Jack Waller will succeed Tony Cusens as President of the Institution 1992-93 at an Ordinary Meeting at Institution headquarters on 1 October 1992. The handover will be at 6 pm when the new President will give his Presidential Address ‘An agenda for a New Age’, the full text of which will be published in The Structural Engineer in November.

Laboratory tests on 15 reinforced concrete external beam/column connections are described. Three reinforcement details were used - bending beam tension steel up or down into the column and the ‘U’ bar - in conjunction with which beam depth, beam tension steel percentage and column load were varied. Internally strain-gauged reinforcement was used to obtain detailed distributions of strain along the beam and column bars and so investigate the intrinsic mechanisms of connection behaviour. Results are presented to indicate the performance of the details under the different test conditions, particularly influences exerted by the test parameters on reinforcement strain distributions. Bond stresses along the beam tension steel are evaluated, and the means by which each detail effected load transfer by bond is described. Recommendations are made concerning the effectiveness and suitability of each detail in practical connection design. R.H. Scott