Flexural tests on X7/5 wire prestressed concrete beams made with High Alumina Cement (HAC) are described. The beams were artificially converted (in the range 10–100±5%) and observations were made on central deflection, strains, ultrasonic pulse velocities, cube compressive and prism flexural strengths, and concrete moduli.
Although the conversion caused some major changes in the concrete properties the effect on the ultimate moment capacity of the beams was minor, due to the under-reinforced nature of this particular section at these particular concrete strengths.
The characteristics of a partial boundary layer wind tunnel are established for simulated air flow over an urban environment and the wind excitation of small cantilever structures is examined. The process of modelling the natural wind is explained and techniques are outlined for the measurement of mean and r.m.s. response of small scale structures. The significance of such information for indicating the dynamic response of large scale structures is discussed.
The logical design of the layout of a multi-storey building is a conceptually and numerically complex task which, if an acceptable algorithm can be devised, is ideally suited to a computer-aided approach.
Previous work in multi-storey layout planning at Liverpool[1] has been concerned with methods of defining vertical links. The present work considers the problem of allocation of activities to the various levels of a multi-storey building and computer-aided solution based on the use of techniques of cluster analysis is proposed. The principles of the computer program are described and its use in multi-storey layout planning is assessed.
This paper describes a study of the performance of pelmet-type wind deflectors. The influence of dimensions and location of the deflector on the magnitude of indoor air motion at various levels above the floor is discussed. It is observed that the availability of air movement at a working plane 0.4 m above the floor can be enhanced by 30 per cent using a pelmet type deflector (height and width equal to 1/4 and 1/6 of the window height respectively) on the inlet. Air motion indoors is reduced when the deflector is fitted on the outlet but the decrease is negligible for a deflector of these dimensions.