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. He stated that results such as the success story of a canal and drainage system construction with the SHC have proven to show that the invention thrives in “coastal communities or tropical regions.” He believed 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 than the original concrete due to its longer lifespan. However, there is a need in the article 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 would have substantiated Spinks’ claim, since it explained 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. It 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 Manikandan’s and Padmavathi’s article in
2015 that the compressive strength of bacterial concrete has 1.25N per mm3
more than the conventional concrete.
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 the longer concrete lifespan, readers would 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. The demand for concrete products will be lowered if it is maintained well. SHC could 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 the chloride ions penetration. In
the article, “Effect on Bacteria on Performance of Concrete/Mortar: A Review”
(2019), Sikder and Saha 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 could be relieved from the corrosion problem of
reinforcing steel. The construction industry could 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 of SHC in the author’s article. Doing so
will provide a more convincing stand about the potential of SHC being the
future sustainable solution in replacing ordinary concrete.
Manikandan, A.T., & Padmavathi,
A. (2015). An experimental investigation on improvement of concrete serviceability by
using bacterial mineral precipitation. International Journal of Research and
Scientific Innovation, 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. https://www.researchgate.net/publication/334626974_Effect_of_Bacteria_on_Performance_of_ConcreteMortar_A_Review
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
Stanaszek-Tomal, E. (2020). Bacteria concrete
as a sustainable building material? Sustainability 2020, 12(2),
696. https://doi.org/10.3390/su12020696
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
No comments:
Post a Comment