No_1_May_and_June__1953 — Page 50

THE AEROCEM CONCRETE SPRAYING PROCESS

THE Aerocem

The Jewish Synagogue on Robinson Road.

Aerated Concrete Spraying Process has been de- veloped to place mechanically aerat- ed cement, concrete and other aerat ed cementitious compounds. The aeration of the concrete is effected by mixing with an Aerocem foaming agent in a specially designed mixer.

The Aerocem technique is similar, in many respects, to that of paint spraying. The Aerocem concrete. after being properly mixed and aerat- ed, is placed in a pressure pot from which it is forced, by compressed air, through a spray gun. The manufac- ture of a suitable gun presented dif- ficulties, but these have been in- geniously overcome. By varying the pressure in the pot and by adjusting the volume of atomising air at the gun nozzle.

finishes varying from rough-cast to fine sandy surfaces can be obtained. If, however, a smooth, trowelled finish is required the con- crete may be trowelled by hand with- out appreciably consolidating the

cellular texture.

ed and the reinforcing much exposed. The results of cladding with aerated concrete are said to be remarkable. and there is little doubt that the Aerocem process is particularly suit- able for such work. It is argued that even if minute hair cracks do, in que course, appear in the aerated con- crete, there will be no appreciable penetration of water and the con- tractors are confident that the clad- ding cannot flake off. That con- fidence they could have with no other form of plastering. If some super- ficial erosion does take place, and this cannot happen for many years, for the cladding is exceptionally hard, the surfaces will be quickly and cheaply restored by spraying on a further thin coat of aerated concrete.

In Singapore an interesting ap- plication of Aerocem work is tne spraying of a cliff surface near the Pasir Panjang Power Station. The cliff surface extends for approximate- ly three hundred feet and is one hundred feet high. It is composed of layers of laterite and clay. Erosion The advantages claimed for the was troublesome, and various methods Aerated concrete of securing the surface were tried process are many.

ordinary without is certainly lighter than

success. Finally, however, concrete and consequently has supe- the whole area was stabilised with a rior thermal insulating properties. thin skin of Aerocem aerated con- For rendering, the cellular texture of aerated concrete make it more water- proof than ordinary plasters, and the fact that it is mechanically placed under pressure gives it superior coloured adhesive properties. work, the colouring material is placed in the concrete. It cannot, therefore, wash off. The process is in fact par- ticularly useful for the repairing and waterproofing of all types of brick and concrete surfaces.

For

In England the authorities of the Port of Bristol have completely cover- ed several large granaries with Aero- cem aerated concrete. The granaries were damaged during the war and, as in the case of many buildings, had not received, during and immediately after the war, the care and main- tenance they required, with the result that the concrete surfaces were erod-

crete.

Another interesting adaptation of this process is the renovation of cor- rugated iron and asbestos structures, such as nissen huts and roofs. The Aerocem technique provides for the covering of such structures with cel- lular concrete, one to two inches thick, reinforced with wire netting or expanded metal. The results of such reconditioning are said to be remark- able and the structures become habit- able, well insulated waterproof build- ings.

The Jardine Engineering Corpora- tion Ltd. has the sole rights in Hong Kong for this process. They contract to do all kinds of Aerocem work, typical examples of which can be seen on the Helena May Institute in Gar- den Road and on the Jewish Synago- gue in Robinson Road.

The Helena May Institute on Garden Road.

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The cliff surface near Pasir Panjang Power Station.

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