Green Cement
Geopolymer Cement
The GREEN CEMENT used by GREEN CONCRETE USA is a geopolymer cement that was developed by Lone Star Industries and a Cemex company called Mineral Resource Technologies. The fact that this GREEN CEMENT was developed and marketed by two large national cement companies makes a strong statement for its proven usefulness.
Pyrament Cement and Lone Star Industries
Lone Star Industries sold a cement called Pyrament in the 1990's. Pyrament was widely used in the mid 1990's. It was used by the US Army, the Corps of Engineers, the Federal Aviation Authority, State Highway Departments, and many others. Hundreds of concrete projects that used Pyrament cement are still in place and are being used today. Type the word "PYRAMENT" into Google. About 400-500 hits should come up showing the widespread use of and documentation of widespread approvals by many states and governmental agencies. The durability and longevity of this cement has also been proven by the many concrete projects still in service, some more than 20 years after they have been installed . Every concrete test imaginable was performed on this cement by Lone Star, governmental agencies, testing labs, ACI, PCA, universities , and others.
Armorcem and Mineral Resource Technologies
Mineral Resource Technologies (MRT), a Cemex Cement company, developed, tested, certified, manufactured, and marketed GREEN CEMENTS from 1998 to 2005. MRT operated a blending facility in Atlanta Georgia during that time where various GREEN CEMENT products were manufactured and sold. Their sales data included testing data, product performance, and product certification data, including ASTM C-1157 certifications. MRT is owned by Cemex. Cemex is one of largest cement companies in the world. Cemex also employs some of the best experts in the world when it comes to cement and concrete technologies.
An American Company Currently Making and Marketing a Green Cement
There is only one company now selling a fly ash based GREEN CEMENT for the US market. That company is called Ceratech, Inc. Their headquarters are in Virginia, and their lab is in Baltimore, Md. (Both MRT (Cemex) and Lone Star Industries have not sold any fly ash based cements in many years.) Ceratech's cement chemistry differs from that used by Pyrament, ArmorCem, and that used by Green Concrete USA. Their chemistry may use a magnesium oxide to convert fly ash into a green ASTM-C-1157 cement. The economics of their cements are unknown. Their cements may cost more since their sales literature talks about "high performance cements". Their web site contains a lot of wonderful information on their cements.
An ASTM C - 1157 Blending Hydraulic Cement
There are two ASTM specifications for hydraulic cements that are widely used. (A third one is for a slag-cement.) One specification, ASTM C-150, is for Portland cement, and is primarily based upon the chemical composition of the cement. The second, ASTM C-1157 is a performance based specification that mainly requires this cement to meet certain performance standards. GREEN CEMENT meets the ASTM C-1157 requirements for a blended cement. The fact that this cement meets an ASTM specification means that users of this cement can feel confident about the safety of their products when it come to product liability issues. In March of 2009, Erika Guerra of Holcim (US) Inc. testified before the US House about ways that the cement industry could become more sustainable. Her solution would be for a wider acceptance of ASTM C-1157 standards allowing for greener cements. She stated that in many parts of the world, blended ASTM C-1157 cements are widely used. Europe and South America use a large amount of blended cements. The Portland cement manufactures would like to sell more ASTM C-1157 cements because they would be greener. GREEN CEMENT can completely replace all of the Portland cement used in making concrete. A General Use (GU) cement meeting ASTM C-1157 specifications now can be widely used by concrete manufactures.
Class C Fly Ash is What Makes Green Cement Green
The main ingredient for a GREEN CEMENT is a Class C fly ash. Fly ash is a fine, glass like powder recovered from gases created by coal-fired electric power generation. U.S. power plants produce millions of tons annually, of which over two thirds, is usually dumped into landfills. Fly ash is widely used by concrete manufactures to replace a portion of the Portland cement used to make concrete. Fly ash usually replaces around 15% to 20% of the Portland cement in concrete. Fly ash is used in about 30% of all the concrete made in the United States. GREEN CEMENT is composed of about 95-98% Class C fly ash. The use of this high percentage of Class C fly ash, which is classified as a recycled material, is what makes this cement GREEN. Portland cements consume a great deal of raw materials and energy in the manufacturing process. Over 7% of all green house gas emissions worldwide are caused from the manufacture of Portland cement. For each ton of Portland cement manufactured, one ton of greenhouse gas (CO2) emissions occur. Each ton of Green Cement made using 95% or more of recycled materials would reduce CO2 emissions by about one ton.
Making Green Cement
Fly ash is hauled directly from the source to the concrete plant. (Or hauled directly to the job site where small portable concrete making equipment is utilized.) Admixtures that convert the fly ash into a cement are added using common admixture equipment. On smaller jobs, admixtures can be added by hand. Approximately 15 pounds of admixtures are added per cubic yard of concrete. Admixtures can be added in a granular or a liquid form. GREEN CEMENT can replace 100% of the Portland cement used in many applications.
Fly Ash Sources and Costs
Both Portland cement and GREEN CEMENT are sensitive to transportation costs. Both cement and fly ash are mostly hauled in cement tankers. The economics for both are best when the sources are located close to the job site or the product manufacturing facilities. Most Class C fly ashes are a result of power plants using and burning Wyoming coals. Most of the middle two thirds of the United States have sources of Class C fly ash. The economics for GREEN CEMENT are good in those areas. GREEN CEMENT would be generally less expensive than Portland cements in the middle two thirds of the USA. The costs of transporting Class C fly ash to both coasts of the USA would make a GREEN CEMENT cost more than Portland cement in those areas. Much of the fly ash sold in the USA is sold by fly ash marketing companies. Some of the companies that sell fly ash include Headwaters, Boral, Lafarge, and MRT. In many good market areas, fly ash sells for around $20.00 to $30.00 a ton. In some places the price is higher, and some places lower. There are numerous ash sources that have unmarketable ash. Also, a lot of sources have excess fly ash that cannot be sold. Additionally, much of the ash produced in the winter time is not marketed. Most all of the ash from these various sources can be used to make a green cement. The economics of a Green Cement work best in those areas that have abundant inexpensive fly ash. GREEN CONCRETE USA has access to over 300,000 tons of inexpensive fly ash from two sources in Illinois. Because of recent air regulations, Illinois has in excess of 1.0 million tons of Class C fly ash that currently goes unused.
Green Cemet Costs Compared to Portland Cement
Portland cement sells for $90.00 to $100.00 per ton in some good market areas of the United States. In other areas and instances, now because of the economy, it sells for $80.00 to $90.00 a ton. The chemical costs of the ingredients added to fly ash to make a GREEN CEMENT are around $25.00 a ton. In one Illinois location near an ash source, the total costs for GREEN CEMENT delivered to a ready mix plant or a concrete products manufacturing facility would be less than $40.00 a ton. Even in areas with $30.00 a ton fly ash, Green Cement would cost around $65.00 a ton. Generally speaking,(in the middle two thirds of the USA) GREEN CEMENT can cost around $40.00 to $65.00 a ton.
Green Cement Business Activities
GREEN CONCRETE USA has proprietary technology that allows for the use of GREEN CEMENT. This cement can be used in many applications and would allow for making products Greener. This technology can be made available to businesses wanting to use and to take advantage of the benefits that this GREEN CEMENT has to offer.