Check out this great article on GreenBiz’s website about greener cement…
Oakland, CA — You don’t have to look far to see just how much concrete humans use. Everything from highways to high-rise and bridges to runways around the world are made with the energy-intensive, carbon-spewing material.
Contributing at least 5 percent of global carbon dioxide (CO2) emissions, the cement industry is ripe for changes to lower its impact. Cement, the glue that binds concrete, is one of the most carbon-intensive materials out there: It produces one ton of CO2 for every ton of cement made.
A number of companies, looking to cut the global impact of concrete, as well as open up huge markets for greener building blocks, are using a variety of methods like replacing concrete ingredients and adding new materials that make concrete waterproof.
The main culprit responsible for the industry’s emissions is Portland cement, the most commonly used type of cement, which is created through an energy-intensive process of crushing raw materials and heating them to up to 3,000 degrees Fahrenheit.
Many companies are reducing the amount of Portland cement needed in concrete by replacing some of it with fly ash, a byproduct of coal-fired power plants. In addition to eliminating some of the emissions and raw materials associated with Portland cement, fly ash makes concrete stronger and easier to work with.
While most companies that use fly ash use it replace between 30 and 60 percent of the Portland cement needed, one company, Ceratech, offers a wide range of cement products (below) that are completely free of Portland cement.
Ceratech’s products contain 35 to 95 percent industrial waste like fly ash and wood ash. Most of the company’s products, which are made through low-energy blending processes, contain 65 percent of higher post-industrial content.
The company also adds a chemical mixture, which Ceratech VP of Marketing Leo Kahl calls a “proprietary secret sauce,” to active the fly ash and make it able to create concrete.
Ceratech makes products for both repairing concrete and laying new concrete (bulk products), its products have been approved for use in 41 states and its has done bridge, highway and other road work for transportation departments in Virginia, Pennsylvania, North Carolina, California and elsewhere.
“There is some reluctance when you get into bulk applications because Portland cement is tried and true and has been around for a long time,” said Ceratech CEO Jon Hyman. But the company has won over a number of customers through using the repair products first. “We put down thousands and thousands of yards of material,” Hyman said.
The Louisiana Tech University’s Geopolymer Laboratory has been working to get rid of Portland cement completely as well by using a hard, cement-like paste known as geopolymer.
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