The latest generation of precast
concrete structural frames has evolved over the past 20 years into buildings of
high specification. Architectural structural precast concrete components are
being used on an increasing number of prestigious commercial buildings, and
steelwork, timber and masonry are being combined for total benefit. Designers
are becoming more aware of the high quality finishes possible in prefabricated
units, but changes are having to be made to the way that the traditional
precast structures are conceived and designed. The construction industry is
calling for multi-functional design, where the optimum use of all the
components forming the building must be maximised.
These lectures concentrate on
skeletal type multi-storey structures, representative of the retail development
and car park. The lectures show that the precast concrete industry is ideally
placed to accommodate the higher demands by using experienced design teams and
skilled labour in a quality controlled environment to produce high
specification components. The important design aspects involving connections,
structural stability, floor plate action and robustness are discussed. A main
conclusion is that the requirement for off-site fabrication will continue to
increase as the rapid growth in management contracting, with its desire for
reduced on-site occupancy and high quality workmanship, will favour controlled
prefabrication methods.
Changes to the way in which the
construction industry should operate in a ‘zero waste and zero defect’
environment were given in the 1998 Egan Report. The Report called for sustained
improvement targets that included reductions of
10% in capital construction
costs; 10% in construction
time;
20% of defects; 20%
increase in predictability.
Further, the report goes on ..…
“The industry must design projects for ease of construction making maximum use
of standard components and processes”. Although the reports did not use the
term ‘prefabrication’, to many people this is what ‘predictability’ and
‘standard components’ means. For the concrete industry this implies precast
concrete.
References
Elliott K.S. and Tovey A., Precast Concrete Frame Buildings - A Design
Guide, British Cement Association, Wexham Springs, Slough,
May 1992, 88pp.
Elliott, K. S., Precast Concrete Structures, Butterworth-Heinemann,
Oxford, 2002,
385p.
Precast Concrete Safety Factors, European Research Final Report,
Contract SMT4 CT98 2276, July 2002.
Elliott, K. S., Multi-storey Precast Concrete Framed
Structures, Blackwell Scientific, Oxford,
1996, 624 pp.
Bruggeling, A.S.G. and Huyghe,
G.F., Prefabrication with Concrete,
Balkema, Rotterdam,
1991, 380pp.
Egan Report, Rethinking
Construction, Department of the Environment, Transport and the Regions, London, 16 July 1998.
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