In the article, "The Self-Healing Concrete That Can Fix Its Own Cracks," Spinks (2015) discusses the possibilities of self-healing concrete (SHC) in the construction industry. According to Spinks (2015), SHC can mend up to 0.8mm cracks of an existing structure. She also cites research from HealCON that revealed the maintenance fee of cracked conventional concrete costs €6 bn yearly. In retrospect, a cubic meter of SHC costs €30 more than the conventional ones. However, Jonkers, the inventor, explained that the invention optimizes the concrete lifetime and reduces maintenance fees. A result such as the success story of a canal and drainage system construction with the SHC has proven to show that the invention thrives in “coastal communities or tropical regions”. He reinstated that SHC has the potential to be a game-changer for investors who are willing to take a risk. At the same time, Spinks states that SHC is a better construction material due to its longer lifespan. However, there is a need for a greater emphasis on the material's properties to convince readers of the invention's potential in replacing original concrete in the future.
The
first material property that Spinks should have compared between SHC and
original concrete is the compressive strength. Stanaszek-Tomal (2020) states
that bacterial activity in concrete can improve the compressive strength of
concrete. She presents several experiment results that proved SHC has 10%
higher compressive strength than ordinary concrete. In my opinion, pointing out
the higher compressive strength data of SHC will substantiate Spinks’ claim,
since it explains that SHC can resist heavier loads if compared to ordinary
concrete. Without the experiment result, the construction industry might
consider SHC to have a weaker compressive strength. They may avoid using SHC as
a construction material because of building stabilization factors. With higher
compressive strength, SHC can be used to manufacture a more stable construction
or infrastructure. This point can be further supported by an article published,
“An Experiment Investigation on Improvement of Concrete Serviceability by using
Bacteria Mineral Precipitation.” (2015).
Secondly, Spinks should have discussed the invention's permeability alongside the self-healing properties in increasing concrete's lifespan. Vijay et al. (2017) note that the bacteria in concrete will absorb water and form carbonate precipitation, causing a reduction in concrete permeability. It is crucial for Spinks to state that SHC has a low permeability as it shows SHC can prevent aggressive chemicals from entering the concrete. Reinforcing steel in concrete is corrosion-free, thus extending the lifespan of the concrete. With that, readers will realize that utilizing SHC will be a better choice in the construction industry. Nowadays, everyone is encouraged to protect the earth as it is the only home for humans. With a longer lifespan, the need for new concrete products will be lower. These potentially decrease the production of concrete products leading to a reduction in carbon emission, protecting the earth from global warming.
One
final material property that Spinks could have discussed is the permeability of
chloride ions in SHC as concrete’s durability is largely affected by it. In the
article, “Effect on Bacteria on Performance of Concrete/Mortar: A Review”
(2019), the authors explain that the formation of calcium carbonate layer
produced by bacteria can resist chloride ion penetration. SHC will have a lower
chloride ion permeability which improves the durability of concrete. With this
statement, the readers can be relieved from the corrosion problem of
reinforcing steel. The construction industry can understand that applying SHC
as a manufacturing ingredient will be better due to its fund-saving in the long-term.
In
a nutshell, the author should have mentioned the material properties stated.
Doing so would provide a more convincing stand about the potential of SHC being
the future sustainable solution in replacing ordinary concrete.
The references:
Spinks,
R. (2015, 20 June). The Self-Healing Concrete That Can Fix Its Own
Cracks. The Guardian https://www.theguardian.com/sustainable-business/2015/jun/29/the-self-healing-concrete-that-can-fix-its-own-cracks
Vijay, K., Murmu, M., & Deo, S. V. (2017).
Bacteria based self-healing concrete- A review. Construction and Building
Materials, 152, 1008-1014 https://doi.org/10.1016/j.conbuildmat.2017.07.040
Stanaszek-Tomal, E. (2020). Bacteria Concrete
as a Sustainable Building Material? Sustainability, 12(2), 696. https://doi.org/10.3390/su12020696
Manikandan,
A.T. & Padmavathi, A. (2015) An Experimental Investigation on Improvement
of Concrete Serviceability by using Bacterial Mineral Precipitation. Int.
J. Res. Sci. Innov., 2, 46–49.
Saha,
P. & Sikder A. (2019). Effect on Bacteria on Performance of
Concrete/Mortar: A Review. International Journal of Recent Technology
and Engineering (IJRTE), 7, 2277-3878.
