I'm beginning to think that my college professors weren't that smart. Maybe that's too strong of a statement. But every time I read a news article or new research item, some basic principal I learned in school is being challenged by a new finding.
In my short lifetime scientists have concluded that Columbus was not the discoverer of America, dinosaurs were more like birds than lizards, and perhaps the most important discovery for me, brain cells do regenerate and can replace themselves.
Fortunately for our industry, researchers and scientists are also looking into the recent past to find ways to secure our future. One example of this historical review is Sulfur Concrete for the Construction Industry: A Sustainable Development Approach. Authors A. M. O. Mohamed and Maisa El Gamal hope to renew interest in the yellow mineral as a cement and concrete alternative to portland cement.
As the concrete industry struggles to find ways to develop more sustainable products, these two respected researchers pose the question, why not sulfur concrete?
The concept of sulfur concrete as a viable material is not new. In the late 1980s and 1990s a committee prepared ACI 548.2, Guide for Mixing and Placing Sulfur Concrete in Construction. That interest was spurred from efforts in 1973. Researchers at McGill University (Mohamed's alma mater) developed a process that modified elemental sulfur by reacting it with olefinic hydrocarbon polymers.
At about the same time, researchers also discovered that a similar reaction would yield a sulfur soluble polymer concentrate. And the ACI committee reported that sulfur concrete was first produced for commercial use in North America in Calgary, Alberta, in 1975.
Three good reasons
Why should our industry reconsider sulfur concrete? The authors offer three valid observations. First, the price of sulfur will be at distressed levels, perhaps providing an economical alternative to higher cost cements. They report that current production levels of sulfur production exceed market consumption. And this gap of waste will continue to expand as environmental regulations continue to increase. “The 21st century sulfur industry will need to expand sulfur in nontraditional markets,” they report.
Second, incorporating sulfur into construction will be viewed positively by society. Using products that would have to be landfilled for constructive purposes is good. And just as important, the authors discuss the durability of sulfur concrete. In many severe duty applications, especially where protective liners are required to extend service life, sulfur concrete can offer a sustainable product of choice.
And third, technological and material improvements may help reduce the production costs of sulfur concrete. The sulfur concrete production process requires a special plant setup. The basic equipment includes a heating device to melt the sulfur, a mixer that blends the molten sulfur with aggregates, and metal molds. The authors describe a precast operation run by Japanese engineers that in 2008 manufactured pipe and manholes for a construction project in the United Arab Emirates.
If I were involved in strategic planning for a precast producer, or a company that wanted to consider new alternative products, I would want this book as a reference. Sulfur Concrete for the Construction Industry represents the most current information on the topic, as the ACI committee has mothballed its 1993 report.
And perhaps in time, thanks to Mohamed and El Gamal, sulfur concrete production will become one of our industry's historical rewrites.