Coal Waste, the Building Block of Society? The use of fly ash in concrete.

Coal has long been a point of contention within America’s society. Coal advocates and environmentalists are always at opposite sides of debates and are involved in a constant struggle with one another. But what if the environmentalists who promote recycling and reuse work together with coal companies to do just that, recycle and reuse. By using fly ash in concrete the coal companies benefit as do those who want to make construction practices less detrimental on the environment and get rid of fly ash.

“Fly ash is made up of fine particulates consisting primarily of silica, alumina, and iron that are collected from flue gases during coal combustion. Flyash is employed as a substitute for some of the portland cement used in the making of concrete, producing a denser, stronger, and slower-setting material while eliminating a portion of the energy-intensive cement required.”

The issue is that both coal and concrete emit large amounts of carbon dioxide. While the detrimental nature of coal is widely known to most, the environmental effects of concrete are less so. Concrete is literally the building block for a majority of modern construction practices. Portland cement , one of the standard elements of concrete, produces 1 ton of CO2 per one ton of cement used during it manufacture. One ton of CO2 emission can be reduced by simply replacing a ton of Portland cement with a ton of fly ash.

The benefits of using fly ash in the mixture of concrete do not stop at the reduction of CO2 in the atmosphere. This method requires less water, improves permeability of concrete, and is stronger. The fact that fly ash cement requires less water will help to combat the global water crisis. Also by having control of the permeability and setting times of the concrete the contractors can set the concrete to the optimal strength needed depending on the job and region. According to CNN, the EPA especially encourages the use of fly ash in concrete because “any heavy metals in the ash are trapped forever.” Perhaps the most important benefit is that fly ash is cost competitive with Portland cement and that is key to changing the way the industry works. Research has even shown that bricks made from fly ash pull minute amounts of mercury out of ambient air. By using fly ash in construction, the environment and the construction industry are not the only ones to benefit. The coal companies get some of their excess waste off of the hands and property. Something they would greatly appreciate. This would help their image and would work to prevent disasters such as the recent TVA spill.

I believe that coal companies and the construction industry need to work more closely with one another to make using fly ash the standard in concrete production. The EPA has already started to get involved by create the Coal Combustion Products Partnership (C2P2) programc (The EPA also has made numerous resources and research readily available on their website that I would recommend checking out for those who want to learn more about fly ash and construction). One of their goals includes increasing the use of coal by-products, such as fly ash, as a supplementary cementitious material in concrete by 50% by 2011. The next step would be a push to make the use of fly ash mandatory when building with concrete, where regionally and economically feasible.