No_2_November_and_December__1948 — Page 51

THE HONG KONG AND FAR EAST BUILDER

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The architect's perspective of the new block of flats for Mollers' Ltd. construction of which is now nearing completion. The distinctive character of the building and the attractive design is well illustrated. Even the car parks and garages are the subject of careful planning and decorative

treatment.

The Architects are Messrs. Palmer & Turner.

LATEX CEMENT AS ADHESIVE IN RUBBER FLOORING By courtesy of the "Indonesian Economic Review".

In a large building here (N.I. Handelsbank) the rubber hall tiles had become loose, the adhesive that had been applied having not been resistant to the tropical climate, su that the tiles began to curl at the corners. This, of course, was objectionable and caused some difficulty to those who had to traverse the halls. Various adhesives were applied, but all of them fortuitously. This happened just before the outbreak of the war.

The NIRO (Netherlands Indies Rubber Research Institute) was approached, which in its laboratory experimented with all kinds of adhesives on a small test floor, such as rubber solutions, mixtures of resins with asphalt, and the like, but without satisfactory results,

Clarkson called attention to the fact that latex cement is very adhesive, as had already been discovered by Wren in England.

The tests were by no means simple, seeing that all former adhesives had to be carefully removed from the tiles, whilst also the cement substratum had to be thoroughly scraped; this cement substratum, having been treated with all sorts of solutions, had lost its porousness, so that the latex cement mixtures could not dry as they should have dried. The results nevertheless were favour- able, and after some experimentation it was possible to instruct a commercial concern with reference to the process to be applied, with a view to its application to the whole of the building in point.

The mixing of latex with cement is primarily intended to make use of the water-binding properties of cement, so that the water in the latex could be bound. This is why

a mixture of latex and cement dries more quickly than a corresponding mixture of latex and clay. The cement, moreover, gives certain mechanical qualities to the rubber, as does any other appropriate substance. According to the proportion of latex in the cement one may obtain, after trying, a substance as hard almost as cement, or as soft and elastic as rubber. All intermediate gradations can be effected, according to the proportions in the mixture.

A latex-cement composition can also serve as rubber flooring. To distinguish it from actual rubber flooring, consisting of tiles or of vulcanized rubber bands, this kind of paving is referred to as latex-cement flooring.

In laying a floor of this kind a layer with a high cement content is spread, over which another layer is spread with a lesser cement content. The third and last layer consists of a mixture with a high rubber content. In this way a good adhesion is effected with the bottom layer.

We cannot explain here the advantages of latex-cement flooring in all its aspects. We may state, however, that in the past war this kind of flooring was largely used on the decks of men-of-war, because it was easy to lay them, they kept a grip on the underlying steel, they adapted them- selves to the motion of the deck, and their surface was non- slippery and proof against the action of sea-water.

Summarizing the above we may say that latex-cement compositions have many applications, and can be used not only for flooring but also as adhesive for rubber tiles and other materials.

G. E. VAN GILS.

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