with conventional methods. Manu- facture in the factory, foundations, erection and floors, equipment and fit- tings take a total of only 850 man hours. compared to 1,300 by tradi- tional methods.
This is the Balency breakdown:
manufacture in factory: 325 hours foundations
erection and floors
30 hours
325 hours
equipment and fittings 170 hours
These times are based on a flat of 750 sq. ft. and it is claimed that the total could be brought down to 700 hours on large contracts. In France the cost of labour in prefabricated construction works out at about 20 to 25 per cent of the cost price of the building.
Moulds
Horizontal moulds are used for the production of the external wall panels which have an internal "sandwich" layer of expanded poly- styrene insulation. The external sur- face of the panel, which is formed of a special layer of concrete incorporat- ing selected aggregates, is placed on the lower face of the panel as it is on the steel face of the mould. The first stage of the finishing process, by which the pieces of aggregate are ex- posed, is carried out while the panel is standing on a rack immediately after being removed from the mould.
Vertical moulds are used for the production of the internal partition wall panels. These panels are cast against polished steel mould surfaces and a smooth finish is achieved on both sides which needs no further work before the final wall finish is applied. Wall panels are cast with all necessary wiring conduits and other service provisions.
Special moulds are used for bal- cony fronts, staircases and other pur- poses, including the "technical block”
..
Model of 15- storey tower block design at Ballymun, N. Ireland
which is a feature of the Balency sys- tem and which is designed to incor- porate all the pipework required to service the kitchen and bathroom in each of the flats.
A unique feature of the vertical moulds in the Balency system is that concrete is injected pneumatically from below. Smoother faces are ob- tained by this method as less air is trapped by the concrete than is the case when concrete is placed vertical- ly from above. Injecting concrete into the bottom of the mould elimin- ates segregation.
The moulds are heated by hot water pipes at a water temperature of 95°C. Heat is applied to all sides of the unit in order to prevent differen- tial curing rates resulting in twisted or curled castings. The method of heating the upper faces of the hori zontal moulds is by "autoclave' hoods. which are hydraulically lowered over the mould. The moulds and heating hoods
operated by hydraulic power through jacks and mould as- sembly striking mechanisms, also hydraulically powered.
IN
Panel of wall of stairwell
Installing a "functional" unit
Far East Architect & Builder August, 1966
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