46
three-quarters of the plan area of the block to be served. It often happens that such concreted areas are even- tually required near the block for a car park, approach road or as ground- floor slabs for one or two-storey
dwellings or garages.
After the initial horizontal casting of each pair of 'master' panels, these are erected vertically, and subsequent similar panels cast between them. The process is repeated until there are sufficient 'battery' units of their kind for one storey.
These battery units are then used to produce like units for all but the top storey before they themselves are lifted and built-in. For most blocks. three or four different batteries will be sufficient for both walls and floors, according to the lengths and breadths of the units required. If similar blocks are required on the same or neighbouring sites, the pairs of bat- tery end-units may be moved to the new casting positions.
The tower crane is fully occupied
in shifting battery units, and handling and placing fresh units. The batteries are therefore filled by a light mobile crane carrying a concrete skip, ap- proaching from the site and discharg- Concrete is ing down a short chute. placed alternately back and forth along a battery, so that the level rises evenly. A long battery may be readi- ly sub-divided into sections (by the use of intermediate soldiers and wal- ings), each of which could be con- veniently filled during periods of con- tinuous working. Battery production is integrated with erection.
The prefabrication of reinforcement is a vital part of the process. Within a short distance of the batteries there is a series of covered bays, the ground floor of the block itself being suitable in this case. Each bay contains a jig for the production of the particular reinforcement required.
After assembly, and sufficient spot- welding to render the mesh reasonably stable. every conduit and outlet, skirting or partition ground, erection
fixing-socket insert which may be re- quired within the particular unit is secured to the mesh, which is num- bered and carried out to a rack ad- jacent to the appropriate battery. It is thus possible for the operatives at the batteries to place everything re- quired within each unit in one short and simple operation.
If an erection cycle of,
Say 15 minutes is used, a small proportion of this time, say 8 minutes, will be spent moving a battery-unit to its new position, and the remaining 12 minutes in hoisting a newly-cast unit into position, returning to the next battery-unit, and thus completing the cycle. It is during the 12 minutes that all necessary preparatory opera- tions for the next new unit within the battery will be done; operations at the sides or top of the battery can be done after it has been reassembled.
In a rational programme of casting, each battery will be fully struck and reassembled in turn. The erection of a storey will, therefore proceed by
BATTERY
CENTRE LINE
OF BUILDING
PANEL
STORAGE
CRANE TOWERI
82
0
MAXIMUM
CRANE
JIB RADIUS
706
1TTT
ДДДДДд
MIXER
151
Fig. 6. Edmonton site plan. Note cladding panels already cast (right and bottom)
ALI
TT
142′ 2′′
Far East Architect & Builder August, 1966