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A discussion of the paper “sulphur impregnated concrete, SIC,” by Niels Thaulow
CEMENT and CONCRETERESEARCH. Vol. 5, pp. 91-92, 1975. Pergamon Press, Inc. Printed in the United States.
DISCUSSIONS
A DISCUSSION OF THE PAPER "SULPHUR IMPREGNATEDCONCRETE, SIC," BY NIELS THAULOW* V. M. Malhotra Head, Construction Materials Section, Mineral Processing Division, Mines Branch, Department of Energy, Mines and Resources, Ottawa, Canada The author has presented an interesting paper describing the use of sulphur for impregnating concrete. The author has also referred to my research on sulphur concrete and Fig. l in his paper is partly based on the data in my report.(1) Unfortunately, data given in reference (1) are obsolete with regard to the price of sulphur. I t is, therefore, f e l t that the following comments on the price of sulphur and also on the impregnation of concrete with sulphur should be of interest. I t is true that in 1972 the price of sulphur in Alberta, Canada was about $6.00 (U.S.) per ton. This is no longer so. The world-wide shortage of materials has also affected sulphur and, as of July 1974, the price of sulphur is about $25.00 (U.S.). This is an almost fourfold increase in less than two years, and i t is possible that the price may even go higher. Thus the price comparison as given by the author, that sulphur is 70 times cheaper than methylmethacrylate is no longer valid. Furthermore, the projection that the inventory of elemental sulphur w i l l accelerate to about 50 million tons by the end of 1980 (1) is now also being questioned. (2) The author's paper appears to convey the impression that the use of sulphur for impregnating concrete is something new. This is not so. The principle of impregnating concrete with sulphur has been known for sometime and this has been reported in the literature. (3) The writer has also been engaged in the impregnating of concrete with sulphur since December 1972 and has obtained considerable increases in the mechanical properties of sulphur i n f i l t r a t e d concrete. Notwithstanding the above, the author has done a commendable job by bringing to the attention of concrete technologists the need for cheaper materials for impregnating concrete, and elemental sulphur is certainly one of them. I t should be pointed out that at elevated temperatures, sulphur i n f i l t r a t e d concrete w i l l suffer from the same disadvantages as the polymer impregnated concrete because sulphur melts at about ll2°C. Thus, like the P.I.C., the sulphur *CCR 4, 269 (1974).
91
92
Vol. 5, No. 1 DISCUSSION
i n f i l t r a t e d concrete cannot be used for load bearing members in structures where there is a p o s s i b i l i t y of exposure to high temperatures. However, like P.I.C., sulphur i n f i l t r a t e d concrete is ideally suited for small precast unit . The sulphur impregnating technique used by the author is identical to that used by researchers in producing P.I.C. This involves both the evacuation and the application of external pressure, and the curing and drying periods are long. Furthermore, the technique is expensive and r e l a t i v e l y complex. Research at the Canadian Mines Branch, Ottawa, is being directed at making the impregnation procedures simple and economically competitive with conventional portland cement concrete. Preliminary results are encouraging. I t appears that the impregnation cycle which normally consists of 28-day curing, drying, impregnating, and testing can be considerably shortened and high strength sulphur inf i l t r a t e d specimens can be produced in less than 3 days after mixing concrete.
.
References V. M. Malhotra, "Mechanical Properties and Freeze-Thaw Resistance of Sulphur Concrete," Department of Energy, Mines and Resources, Ottawa 1973, 30 pp. Series: Mines Branch Investigation Report IR 73-18.
.
G. H. K. Pearse, "Sulphur - Economics and New Uses," Mineral Resources Branch, Department of Energy Mines and Resources, Ottawa, Canada, February 1974, 17 pp.
.
Alan H. Vroom, "Sulphur in Concrete," paper presented at the 7th Annual Seminar of the Canadian Capital Chapter, American Concrete I n s t i t u t e , Ottawa, November 1972 (available from: Secretary, Canadian Capital Chapter ACI, P.O. Box 3005, Station C, Ottawa, Canada).
DISCUSSIONS
A DISCUSSION OF THE PAPER "SULPHUR IMPREGNATEDCONCRETE, SIC," BY NIELS THAULOW* V. M. Malhotra Head, Construction Materials Section, Mineral Processing Division, Mines Branch, Department of Energy, Mines and Resources, Ottawa, Canada The author has presented an interesting paper describing the use of sulphur for impregnating concrete. The author has also referred to my research on sulphur concrete and Fig. l in his paper is partly based on the data in my report.(1) Unfortunately, data given in reference (1) are obsolete with regard to the price of sulphur. I t is, therefore, f e l t that the following comments on the price of sulphur and also on the impregnation of concrete with sulphur should be of interest. I t is true that in 1972 the price of sulphur in Alberta, Canada was about $6.00 (U.S.) per ton. This is no longer so. The world-wide shortage of materials has also affected sulphur and, as of July 1974, the price of sulphur is about $25.00 (U.S.). This is an almost fourfold increase in less than two years, and i t is possible that the price may even go higher. Thus the price comparison as given by the author, that sulphur is 70 times cheaper than methylmethacrylate is no longer valid. Furthermore, the projection that the inventory of elemental sulphur w i l l accelerate to about 50 million tons by the end of 1980 (1) is now also being questioned. (2) The author's paper appears to convey the impression that the use of sulphur for impregnating concrete is something new. This is not so. The principle of impregnating concrete with sulphur has been known for sometime and this has been reported in the literature. (3) The writer has also been engaged in the impregnating of concrete with sulphur since December 1972 and has obtained considerable increases in the mechanical properties of sulphur i n f i l t r a t e d concrete. Notwithstanding the above, the author has done a commendable job by bringing to the attention of concrete technologists the need for cheaper materials for impregnating concrete, and elemental sulphur is certainly one of them. I t should be pointed out that at elevated temperatures, sulphur i n f i l t r a t e d concrete w i l l suffer from the same disadvantages as the polymer impregnated concrete because sulphur melts at about ll2°C. Thus, like the P.I.C., the sulphur *CCR 4, 269 (1974).
91
92
Vol. 5, No. 1 DISCUSSION
i n f i l t r a t e d concrete cannot be used for load bearing members in structures where there is a p o s s i b i l i t y of exposure to high temperatures. However, like P.I.C., sulphur i n f i l t r a t e d concrete is ideally suited for small precast unit . The sulphur impregnating technique used by the author is identical to that used by researchers in producing P.I.C. This involves both the evacuation and the application of external pressure, and the curing and drying periods are long. Furthermore, the technique is expensive and r e l a t i v e l y complex. Research at the Canadian Mines Branch, Ottawa, is being directed at making the impregnation procedures simple and economically competitive with conventional portland cement concrete. Preliminary results are encouraging. I t appears that the impregnation cycle which normally consists of 28-day curing, drying, impregnating, and testing can be considerably shortened and high strength sulphur inf i l t r a t e d specimens can be produced in less than 3 days after mixing concrete.
.
References V. M. Malhotra, "Mechanical Properties and Freeze-Thaw Resistance of Sulphur Concrete," Department of Energy, Mines and Resources, Ottawa 1973, 30 pp. Series: Mines Branch Investigation Report IR 73-18.
.
G. H. K. Pearse, "Sulphur - Economics and New Uses," Mineral Resources Branch, Department of Energy Mines and Resources, Ottawa, Canada, February 1974, 17 pp.
.
Alan H. Vroom, "Sulphur in Concrete," paper presented at the 7th Annual Seminar of the Canadian Capital Chapter, American Concrete I n s t i t u t e , Ottawa, November 1972 (available from: Secretary, Canadian Capital Chapter ACI, P.O. Box 3005, Station C, Ottawa, Canada).