Carbon dioxide in the atmosphere has been a problem for humanity ever since the Industrial Revolution, which brought us new mechanical technology for more convenient work. However, the carbon dioxide that has been released into the air since the 18th century has built up causing global warming, which is exactly like it sounds: The Earth is warming up. Since the Industrial Revolution, another form of releasing carbon dioxide into the atmosphere has been invented, Cement, the mixture of limestone and sand that builds out buildings and sidewalks, does release a large amount of carbon dioxide into the atmosphere. The carbon dioxide is released two ways: 1) Through the heat machine that burns fossil fuels. 2) When the limestone in the cement is heated up, it is separated into lime and carbon dioxide. So, how do we fix this problem?
There is a substance similar to cement called flyash. When coal is burned in power plants, what is left over is flyash. Flyash is usually dumped without consideration because it is considered as a waste product, but flyash can reduce carbon dioxide being released through the atmosphere through cement, and at the same time, reduce flyash being dumped in the landfills. Additionally, flyash is overall a better cement than cement because it doesn't crack as easily, and also it lasts much longer than cement.
Investigating the Issue
Investigate issues that influence the decision to use flyash. Discuss the advantages and disadvantages of flyash.
1. Flyash is ECO-FRIENDLY.
“Although flyash offers environmental advantages, it also improves the performance and quality of concrete. Flyash affects the plastic properties of concrete by improving workability, reducing water demand, reducing segregation and bleeding, and lowering heat of hydration. Flyash increases strength, reduces permeability, reduces corrosion of reinforcing steel, increases sulphate resistance, and reduces alkali-aggregate reaction.”
2. Flyash is CHEAP.
“Flyash concrete is the same price as ordinary concrete without flyash. EPS wall-form products provide a cost-effective wall. Fiber-cement wall-form cost approximately $3.50 per square foot of wall surface.”
3a. Flyash is potentially DANGEROUS.
"There is a small segment of the population that is fearful of flyash being inferior or unhealthful. U.S. EPA information indicates there is not a health threat, especially in the portions found in ready-mix products and with western coal (which is the primary source of local flyash). A concrete finish floor may sound less desirable aesthetically to some persons. However, coloring, scoring, and texturing techniques can be very attractive."
3b. Flyash is potentially DANGEROUS
“Since coal contains trace levels of trace elements (like e.g. arsenic, barium, beryllium, boron, cadmium, chromium, thallium, selenium, molybdenum and mercury), fly ash obtained after combustion of this coal contains enhanced concentrations of these elements, and therefore the potential of the ash to cause groundwater pollution needs to be evaluated."
3c. "Fly ash contains trace concentrations of heavy metals and other substances that are known to be detrimental to health in sufficient quantities.”
3d.“Crystalline silica and lime along with toxic chemicals are among the exposure concerns. Although industry has claimed that fly ash is "neither toxic nor poisonous," this is disputed. Exposure to fly ash through skin contact, inhalation of fine particle dust and drinking water may well present health risks.”
Overall, flyash is eco-friendly, and has many benefits. But, the only thing keeping from being used more often is the fear of it being harmful through metals and substances from the power plant.