Summary_Reader Response Draft #4: Coal ash into concrete

-
The NaturalBlaze.com article, "Researchers Turn Waste from Coal Power Plants into Concrete" (2019), reports that researchers from Drexel University have discovered a sustainable solution to protect the natural environment and improve the built environment by recycling coal ash. Coal ash, a harmful byproduct of coal-fired power plants, ends up abundantly in landfills each year. Concrete is one of the most popular building materials in the world but one drawback is that it requires the right atmospheric conditions to allow proper mixing and curing. The article states that by turning these waste coal ash into a special additive, “spherical porous reactive aggregate” (SPoRA) and adding them into the concrete while curing process, it will improve the durability and quality of the concrete (as cited in the journal “Cement and Concrete Composites”). By using this method, it will reduce the number of coal ash in landfills and benefits the industry.

 While agreeing with the method of using SPoRA in concrete reduces cost and benefits the concrete industry based on the points elaborated in this article, the information regarding types of SPoRA, and the time, it is suitable to use are not stated in the article.

 The builders and housing contractors may not be familiar with coal ash products, which can have different properties depending on where and how it was obtained. The poor quality of coal ash can increase the permeability of the concrete and cause damage to the building. Federal Highway Administration (2016) states that there are two classes of fly ash for use in concrete: class F, usually derived from the burning of anthracite or bituminous coal, and class C, usually derived from the burning of lignite or sub-bituminous coal. The use of class F fly ash usually results in slower early strength development, but the use of class C fly ash does not enhance early strength development. The article also mentions the sources of ash which should be avoided to ensure the quality of fly ash for use in Portland cement concrete. The type of coal ash is important for the contractors as the coal ash lowers the hydration temperature of concrete and prolongs the setting time. Therefore, it will be the best if the researchers add the admixtures to the SPoRA and separate them into sub-groups depending on the places they can be used.

 The coal ash also affect its use in concrete. VandeWater (2016) states that it is more difficult to control the color of concrete containing coal ash than mixtures with Portland cement only and the color charts will not be completely accurate. Coal ash also may cause visual unpredictability in the finished surface, such as dark streaks from carbon particles. For this reason, the researchers should announce the warning that it will be a good idea for the contractor to make a mock-up sample before he use it.

 Although coal ash in concrete is great in many applications and improves performance in some ways, but it also has some disadvantages. Therefore, the article should indicate the information regarding types of SPoRA as it is important for the contractors.

 References

 Federal Highway Administration. (2016). User guidelines for waste and byproduct materials in pavement construction: Coal fly ash. Retrieved Feb-01-2020 from
https://www.fhwa.dot.gov/publications/research/infrastructure/structures/97148/cfa53.cfm

Researchers turn waste from coal power plants into concrete (Oct-29-2019). NaturalBlaze. Retrieved Feb-01-2020 from
Rodriguez, J. (2019, February 17). Uses, benefits and drawbacks of fly ash in construction. The pros and cons of using fly ash in your concrete. The Balance Small Business.
Retrieved Feb-03-2020 from 
Team McCoy Mart. (2019, November 29). What are the advantages and disadvantages of using fly ash in concrete?. 
Retrieved Feb-03-2020 from
https://mccoymart.com/post/advantages-disadvantages-using-fly-ash-concrete/

 VandeWater, S. (2016, April 16). How fly ash can affect concrete color and performance. Indiana Decorative Concrete Network. Retrieved Feb-02-2020 from 

Wilder, C. The disadvantages of fly ash in concrete. 
Retrieved Feb-02-2020 from



Comments

Post a Comment

Popular posts from this blog

Introduction Letter

-
Dear Professor Brad, My name is Tha Zin Wint Htel but feel free to address me as Thazin. I would like to introduce myself to you as a first year engineering student from Singapore Institute of Technology (SIT).   Since I was young, I have enjoyed mathematics and have also been fond of looking at the unique designs of the buildings. In 2016, after my high school matriculation exam, I came to Singapore for summer holidays. During my stay here, I took an entrance exam for construction engineering course and got an opportunity to study basic knowledge about designs and structures of the construction works at Building Construction Authority Academy (BCAA) and graduated in 2019. I spent fifteen years of my youth in Myanmar and learnt English as a second language. I can say that I'm an active listener because I always pay attention and respect the person who is speaking to me. I avoid other distractions such as cell phones or laptops, and I prepare comments or ideas to respond ...
Read more

Annotated Summary

-
Solid waste management infrastructure (n.d.). National Environment Agency. https://www.nea.gov.sg/our-services/waste-management/3r-programmes-and-resources/waste-management-infrastructure/solid-waste-management-infrastructure This article states that as Singapore is growing population, the amount of solid waste disposed has been increased from 1,260 tonnes a day in 1970 to a peak of 8,559 tonnes a day in 2016. Currently, Singapore's solid waste disposal infrastructure consists of four waste-to-energy (WTE) plants, Tuas, Senoko, Tuas South and Keppel Seghers Tuas Waste-To-Energy Plant (KSTP), as well as the Semakau Landfill. Before collecting the solid waste, the recyclables are sorted and retrieved for processing to prolong the lifespan of recyclable materials. The solid waste that remains is then collected and sent to the various waste-to-energy plants for incineration. The incineration of solid waste reduces its volume by about 90% and produces steam, which runs turbi...
Read more

Critical Reflection

-
The learning journey with Professor Brad in the effective communication module has been a remarkable experience. Since the module was started, he asked to write an introduction letter including weakness and goals. At there, I set my goals to have a greater confidence, enjoy public speaking and make new friends by the end of this module. Now it has already been 13 weeks and I realize that I do improve not only my communication but also reading and technical writing skills. During his class, I was urged to cooperate in class activities like rephrasing with citations and presenting ideas to the class. As I'm a silent person, I barely speak out loud and express my thoughts to the class but these activities encouraged me to improve on my articulation of words. One of the assignment was to write a summary and reader response of an article. As it was my first time writing an analysis, I was hesitant in my work. But with the clear feedback from Professor, I was able to carry out the t...
Read more