Summary Reader Response Draft # 2

     In the article, "The Self-Healing Concrete…" Spinks (2015) discusses the possibilities of self-healing concrete (SHC) in the construction industry. According to Spinks, Jonkers, the inventor, explained that the invention optimizes the concrete lifetime and reduces maintenance fees. She also mentions that SHC can mend up to 0.8mm cracks of an existing structure. Spinks cites research from HealCON on the maintenance cost of cracked old-fashioned concrete for the fundamental infrastructure in the EU being €6 bn yearly. However, she remarks that a cubic meter of self-healing concrete is 30€ more expensive than standard concrete. Jonkers mentioned that he had constructed a canal and drainage system with the invention. His project can be a successful record to convince the building industry. He also went on to mention how any coastal society can obtain advantages from it. He concluded that SHC could be a game-changer for the future of risk-taking investors in the construction field. At the same time, Spinks states that SHC is a better construction material due to its longer lifespan. However, she needs to emphasize more on the improved material properties of SHC due to bacteria if she wants her readers to believe that it can replace standard concrete in the future building industry.

    First and foremost, Spinks should have compared the compressive strength between SHC and standard concrete to show the advantages of SHC. Elzbieta (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 would mean that SHC could resist heavier loads if compared to ordinary concrete. Without the experiment result, the construction industry might consider SHC to have a weaker compressive strength. Hence, 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 …” (2015).

    Secondly, Spinks only mention that the self-healing properties of SHC can increase the lifespan of concrete but fail to mention its permeability that has a similar effect. Kunamineni et al. (2017) notes that the bacteria in concrete will absorb water and form carbonate precipitation, causing a reduction in concrete permeability. I think it is crucial for Spinks to state SHC has a low permeability as it would mean that SHC can prevent aggressive chemicals from entering the concrete. Therefore, 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, we are 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.

     Lastly, Spinks should discuss chloride ion permeability in SHC, which can affect the durability of concrete. In the article, “Effect on Bacteria…” (2019) the authors explain that the formation of calcium carbonate layer produced by bacteria can resist chloride ion penetration. Hence, SHC has 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. They can understand that applying SHC as a manufacturing ingredient will be better due to its improved chloride ion resistance.

    In a nutshell, Spinks should elaborate more on the better material properties of SHC in the article to convince the construction industry that it can replace standard concrete as a construction material.

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

    K.Vijay, M. Murmu, and S. V. Deo (2017, 15 July). Construction and Building Materials. Science Direct https://reader.elsevier.com/reader/sd/pii/S0950061817313752?token=6C82D31EC054641C6295A82F1163C1CFBF535E83787AA37FA37208060D25A8702D065FDB973BD2B8106811F01DDC2A1A

E. Stanaszek-Tomal (2020, 17 Jan). Bacteria Concrete as a Sustainable Building Material? MDPI https://www.mdpi.com/2071-1050/12/2/696

Manikandan, A.T.; Padmavathi, A. An Experimental Investigation on Improvement of Concrete Serviceability by using Bacterial Mineral Precipitation. Int. J. Res. Sci. Innov. 2015, 2, 46–49. https://www.researchgate.net/profile/Atmanikandan/publication/316644933_An_Experimental_Investigation_on_Improvement_of_Concrete_Serviceability_by_using_Bacterial_Mineral_Precipitation/links/59099b94a6fdcc49616833c6/An-Experimental-Investigation-on-Improvement-of-Concrete-Serviceability-by-using-Bacterial-Mineral-Precipitation.pdf

P. Saha, A. Sikder (2019, July). Effect on Bacteria on Performance of Concrete/Mortar: A Review. ResearchGate https://www.researchgate.net/publication/334626974_Effect_of_Bacteria_on_Performance_of_ConcreteMortar_A_Review