Summary_reader response draft #3

In the MIT technology review, “What Happened to green concrete?”, Majcher (2015) stated that the intention for producing concrete that absorbs carbon dioxide was to reduce the 5 percent of global carbon dioxide emissions which concrete accounted for. However; due to lack of support, the idea did not make progress, instead, the author introduced other technologies such as nanoengineering and fly-ash. The author mentioned that in 2010, Novacem, a green cement company, found a way to substitute Portland cement with magnesium oxide material that captures carbon dioxide when mixed with water. However, due to a lack of support, it resulted in their eventual liquidation. The author also mentioned, “Storing carbon dioxide in cement is not the only way to improve the material’s environmental footprint.” For instance; MIT’s Concrete Sustainability Hub showed that concretes created from nanoengineering procedure were twice as resistant to breaking and allow lesser concrete used for building constructions. Another way was modifying the properties of concrete by mixing with fly-ash.

The ideal way is to have zero carbon emission from concrete usage. However, green concrete does not garner enough support from researches. I believe the writer should have explained the research on green concrete to show why green concrete is not feasible.

One of the reasons why the research on green concrete is not feasible is the risk. Baggaley (2018) mentioned in her article that scientists have been tinkering with concrete by adding graphene to make it stronger and greener. She included in her article by Dr. Rackel San Nicolas, a civil engineer at the University of Melbourne in Australia and an expert on advanced construction materials, that more research must be conducted to determine whether "tiny graphene particles would pose any health or environmental risks." This shows that the constructions are not ready for sustainable concrete at the moment.

Another reason Majcher (2015) however did not mention the disadvantages of producing green concrete. Bandakkanavar (2014) mentioned that the main disadvantage of using green concrete is that it is not suitable to be used for constructing bridges or dams as it has less life than portland concretes. If green concretes are to be used for bridges, or dams, special air-entraining agents will be mixed in it which therefore increase the overall cost. This explains why most green concrete was used on a small scale and also lacking support.

Lastly, Bandakkanavar (2014) mentioned in his limitation of green concrete that "the split tensile strength of the green concrete is less than the conventional concrete. Thus more reinforcements are needed, which increases the construction cost of the structure". This shows that the enhancement process needed to produce green concrete will result in green concrete being more costly which is not feasible in the long run.

The author concluded that although green concrete was not successful, the takeaway was that cement factories and processes helped to enhance industry energy efficiency by 40% since the 1970s, helping in reducing global carbon dioxide emission.

References:

Baggaley K. (2018).  'Green' concrete could be game-changer for construction industry
Retrieved May 03, 2018 from 'Green' concrete could be game-changer for construction industry

Majcher, K. (2015). What Happened to Green Concrete?

Retrieved March 19, 2015 from What Happened to Green Concrete? - MIT Technology Review

Bandakkanavar R. (2014). Green Concrete
Retrieved September 08, 2014 from Green Concrete - Krazytech