Summary_Reader Response Draft #3: 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. 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 type of coal ash is important for the
contractors as the coal ash lowers the hydration temperature of concrete and
prolongs the setting time. Especially in hot weather, this can be very helpful.
But based upon the particular needs, some concrete contractors may view slower
set times and longer cure times as a liability. They might want the concrete to
set faster because it saves labor costs by reducing man-hours. Perhaps the
weather is getting cold and they need the concrete to set more quickly to avoid
freezing. 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.
Moreover, smaller 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. 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
Researchers Turn Waste From Coal Power
Plants Into Concrete (Oct-29-2019). NaturalBlaze. Retrieved, Feb-01-2020, from
VandeWater,
S. (2016, April 16). How Fly Ash Can Affect Concrete Color and
Performance.
Retrieved,
Feb-02-2020 from
Wilder,
C. The Disadvantages of Fly Ash in Concrete.
Retrieved,
Feb-02-2020 from
Team McCoy Mart. (2019,
November 29). What are the advantages and disadvantages of using Fly ash
in Concrete?.
Retrieved,
Feb-03-2020 from
Rodriguez, J. (2019, February
17). Uses, Benefits and Drawbacks of Fly Ash in Construction.
Retrieved,
Feb-03-2020 from
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