The Effects of Alkali-Silica Reaction on the Strength of Prestressed Concrete Beams

What follows is based on a contribution I was asked to make to the Institution’s Informal Study Group ‘Qualitative Analysis of Structural Behaviour’ at a meeting held to consider ‘Graduate understanding of structural behaviour’. My task was to give the perspective of a large practice; in developing such a perspective, I consulted many colleagues and found a remarkable unanimity of opinion. Nevertheless, the views expressed are not those of the Ove Arup Partnership, but my own. P.M. Morreau

The paper describes an experimental investigation into the behaviour of four full-scale composite beams. Each beam comprised a slab, cast using profiled steel decking, acting with a steel universal beam section. The connection between slab and beam was made using stud shear connectors welded through the profiled steel sheeting. Relatively few connectors were used as the main aim of the investigation was to study the behaviour of such beams with shear connection levels of less than 50 % of that required to ensure full shear connection. A secondary aim of the work was to investigate whether or not the web-cleated end connections acted as pinned supports as assumed in the design. Comparisons between roller supports and web-cleated connections were therfore made during testing. Measurements of the natural frequency of the beams were also made. H.D. Wright and R.W. Francis

Mr R. Campion (British Railways Board) The authors are to be congratulated on preparing an alternative design for this bridge, within a very short timescale, that managed to combine both visual and structural elegance. It was a fitting reward that the bridge should have received a commendation in the Structural Steel Design Award scheme.