Reducing Delay Through Road Lay-up.
Page 26
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A Cement Which Matures in 24 Hours.
THE METHODS of manufacture, physical and chemical characteristics, and ordinary usages of Portland cement are so well known to engineers and architects that only a brief reference may be needed here, and that only for the purtmse of affording a basis of comparison with the remarkable product known as "Ciment Fondu," which is a French production: The current specification of the British Engineering Standards Committee for Portland cement states that Portland cement shall be manufactured by intimately mixing together calcareous and argillaeeous materials, burning them to a clinkering temperature, and .grinding the resulting.slinker so as to produce a cement capable of complying with this specification."
" Ciment Fondu," as distinguished from Portland cement, introduces an entirely new characteristic, the influence of which upon the design of concrete structures of the future can hardly be over-estimated. It is claimed for Ciment Fondu that, although it meets C42 the physical requirements for slow setting cement laid down in the British standard specification, . it matures so rapidly after setting that, at the age of 24 hours after gauging, its resistance to load equals that of normal Portland cement at a month. It is further stated that Ciment Fondu is indecomposable by the action of sea-water and by sulphur-impregnated water or earth.
The discovery of Ciment Fonda was the result of long and patient research undertaken in the laboratory of the producer. In the course of this research Ciment Fondu was obtained and the process was protected in France in 1908. The production of an indecomposa,ble cement proved the theory which prompted the research, hut the extraordinary property of rapid maturity was not foreseen. The significance of this new feature of any cement led to further investigations and from 1908 to 1914 practically continuous experiments were carried out, until the fact was established that. the cement could be produced in commercial quantities of consistent composition and strength, although the cost was rather high.
It was not, however, until the end of 1918 that Ciment. Fondu was put on the market, the war having suspended work in the direction of commercial output. Towards the end of the war, when in pursuit, of the enemy, advanced concrete emplacements for heavy guns were prepared with Ciment Fondu. For the first time in history—artillery" history in any case—positions could he chosen one day and made ready in 48 hours for the reception of the heaviest artillery.
The above notes on Ciment Fondu are from a paper read by Mr. Herbert J.
Davey, M.B.E., berore the Institute of Engineering Inspection. Ciment Fonds!, although costly at the present Ow, is likely to play a very important p:fft in the construction. and re7 construction of roads in the future, especially in the relaying of congested streets in busy cities, where the inconvenience caused by the diverting of traffic is of more consequence than first cost.