July 1, 1997 For Immediate Release
A PRACTICAL NEW WAY TO REDUCE GLOBAL WARMING
One reason that the U.S. has made little progress in meeting commitments to reduce greenhouse gas emissions is that some new technologies designed to mitigate the problem have not been afforded the priority that would allow them to compete in the market. An example is a remarkable cement/concrete technology called geopolymeric cement that can significantly reduce global CO2 (carbon dioxide) emissions, while solving a host of other problems without creating new ones.
Emissions of CO2 from cement production is increasing at a much more rapid rate than all other industrial sources put together. Few outside of the construction industry are aware that the manufacture of Portland cement based concrete, the material seen everywhere in buildings and pavements, emits greenhouse gases, especially CO2. By the year 2000, almost 10% of all global greenhouse gases will come from new construction with Portland cement based concrete. As countries develop, they build infrastructure and housing that utilize abundant quantities of concrete. As global development increases, Portland cement manufacturers can be expected to exert an increasingly greater influence on governmental policies regulating CO2 emissions, a situation that needs to be corrected as soon as possible. By the year 2015, global CO2 emissions from the manufacture of Portland cement is expected to be 3,500 million tonnes annually. This vast amount is equivalent to EuropeÃs total current annual CO2 emissions. This equals 67% of present annual U.S. CO2 emissions (5,160 million tonnes). Clearly, these figures show the dramatic benefit that would be realized if all countries converted to geopolymeric concrete.
Manufacturing geopolymeric cement generates five (5) times less CO2 than does the manufacture of Portland cement. Any country that converts to the manufacture of geopolymeric cement/concrete would eliminate 80% of the emissions generated from the cement and aggregates industries. Newly developing countries that elect to utilize geopolymeric concrete could increase their construction rate five times without increasing present CO2 emissions.
The thermal processing of naturally occurring compounds of aluminum and silica (geological resources available on all continents) provides suitable raw materials for manufacturing geopolymeric cements. A detailed survey of geological resources in Europe and the U.S. shows abundant amounts of suitable natural resources, and laboratory experimentation bears out the viability of making geopolymeric cements with these materials. The resulting concrete has superior properties to Portland cement based concrete. While Portland cement/concrete endures for no more than 150 years in the most ideal environment, geopolymeric concrete can withstand thousands of years of harsh environmental conditions of all kinds. Geopolymeric concrete is durable enough to afford permanent roads and bridges. Thus geopolymeric infrastructure will require very little repair ever, allowing a tremendous reduction in the amount of money that would otherwise have to be spent on the on-going repairs of crumbling roads, bridges, sewer systems, and other elements of infrastructure.
Geopolymeric concretes are the modern counterparts of ancient concretes, such as certain Roman concretes, that have survived in extremely harsh environmental conditions for thousands of years. Geopolymeric concretes are actually man-made rock. The chemistry of geopolymerization is based on the same geosynthesis that occurred in nature to produce over 55% of the Earth's crust. As such, when geopolymeric cement is mixed with natural rock aggregates, the resulting concrete retains the beauty and excellent properties of strong natural rock.
The price of geopolymeric cement/concrete can be competitive with that of Portland cement, assuming natural resources are employed in its manufacture. As well, some waste materials, including fly ash and mining wastes, contain ingredients that produce a geopolymeric chemical reaction, and thus also support the economical manufacture of geopolymeric cement. When mining wastes are encapsulated in geopolymeric concretes, these mineral wastes are more strongly bound than in their natural ores, so that encapsulated waste will not leach out even under the worst possible environmental conditions.
Geopolymeric concretes are currently being used on a small scale for environmental restoration. At the Soviet-abandoned Wismut uranium mining facility in East Germany, geopolymers are being used to treat soils contaminated with uranium waste and other hazardous by-products of uranium mining. Geopolymeric concretes can safely encapsulate hazardous wastes that remain problematic with other means of containment. Briefly referenced by President Clinton with great pride during a re-election campaign speech, a small-scale project is testing geopolymeric composite materials for retrofitting buildings in earthquake-prone areas of the U.S. Geopolymeric concretes and composite materials can also fireproof buildings. Testing by the FAA has shown that geopolymeric composites will not ignite at all.
Even if a technology is clearly superior, it is very difficult for it to displace an entrenched technology. Thus special priority should be given to proven technologies that can dramatically mitigate the tragedies resulting from the severe floods and droughts expected from global warming. Priority status is especially needed in this case because the cement industry has been unwilling to embrace geopolymeric concrete or any other concrete that might threaten to displace Portland cement/concrete. While President Clinton is probably so far unaware of this matter, the replacement of Portland cement with geopolymeric cement will substantially reduce global greenhouse gas emissions, and should be among the measures expected to be recommended by him.
For more information contact:
The Geopolymer Institute
Dr. Joseph Davidovits
[email protected]
http://www.insset.u-picardie.fr/geopolymer/
RSS