Summary_reader response Draft #3

In the article "What Happened to Green Concrete?", Majcher (2015) stated despite the existence of green concrete and its benefits, the application was uncommon as it failed to garner industry’s support. The technology also did not advance over the years. She mentioned that Novacem, the forefront of green cement in 2010, ended in 2012 due to poor investment for its green concrete technology. Calera another company, changed its focus to commercialise its green concrete technology with fibre to make boards for toilet usage, a more lucrative process.

Majcher cited that CarbonCure, on the other hand, sold green cement that had been utilised by approximately 20 projects in the 2 years since it had started. The technology only helped decrease carbon footprint by 5% but more if the carbon was self-captured by the plant. The production could not be in-situ at the project site but was still under development. She also reported that Solidia Technologies' green concrete was stronger and crack resistant but had not advanced since 2008 even with supports from big companies like Lafarge. 

Majcher wrote how Nanoengineering and fly ash inclusion could help to reduce "material environmental footprint". In 2014, MIT's Concrete Sustainability Hub published that nanoengineered concrete could resist fracturing better and reduce cement usage. Meanwhile, CeraTech found that replacing Portland cement with 95% fly ash not only reduced carbon emission (since it cured under chemical reaction) and water by half but landfill usage too.

While Majcher listed the development of various companies’ technologies and their means of carbon emission reduction, she failed to elaborate on what are the underlying factors that hindered the industry players from utilising the technologies.

One factor that prevents utilisation is the effective cost of green concrete. Majcher reported on green concretes’ environmental benefits but failed to mention that technically the effective cost is lesser than concrete. In the article by Williams (2018), he quoted Shahsavari, an assistant professor of civil and environmental engineering and of materials science and nanoengineering, that "environmental benefits" are neutralised with the requirement for costly "sodium-based activators" for substituting Portland cement with fly ash. An article by Baggaley (2018), quoted Dr Franz-Josef Ulm, faculty director of the Concrete Sustainability Hub at MIT, where he had reservation for graphene (a nano-engineered material) due to its cost citing ‘it was more of a "concept material"'. These explain the industry’s hesitance in utilising costlier green concrete, as cost-effectiveness is crucial in sustaining a business.

The broad application of green concrete would also be dependent on the technical benefits. Majcher listed down how some of the technologies resulted in durability, fracture resistance and strengthening. However, she neglected other compromised concrete factors like creep, shrinkage and flexural strength. Based on the journal by Chhipa, Jain and Ram (2018), it mentioned that green concrete has decreased flexure strength and high creep and shrinkage. These suggest the limitation of green concrete application as it is not flexible for usage like earthquakes prone areas. High deformations resulted from the creep and shrinkage suggested restriction of application to less intensive load situation. The limited technical benefits of green concrete lead to restricted application results in the favour of concrete.

Another factor that prevents utilisation is the lack of knowledge on the plausible negative effects green concrete brings. In Majcher’s article, nanoengineered green concrete was reported to reduce cement usage without compromising strength. However, according to Baggaley (2018), she quoted Dr Rackel San Nicolas, “a civil engineer at the University of Melbourne in Australia and an expert on advanced construction materials”, research is still on to rule if there are “any health or environmental risks” result from the tiny graphene particles. The requirement of more assessment on green concrete’s adversity explains the uncommon application of green concrete technologies.

In conclusion, Majcher should also include the underlying reasons why the industry was not pushing for the use of green concrete, allowing readers to gain insights based on perspectives from both consumers and suppliers of green concrete.

References

Baggaley, K. (3 May, 2018). 'Green' concrete could be game-changer for construction industry. Retrieved 1 February, 2019, from MACH: https://www.nbcnews.com/mach/science/new-green-concrete-could-be-game-changer-construction-industry-ncna870371

Chhipa, N., Divyank, J., & Jeeya, R. (2018). A Review Paper on Green Concrete. International Journal of Engineering Research, 7(Special 4), 563-565. Retrieved from http://ijer.in/publication/v7/173.pdf

Majcher, K. (19 March, 2015). What Happened to Green Concrete? Retrieved 24 January, 2018, from MIT Technology Review: https://www.technologyreview.com/s/535646/what-happened-to-green-concrete/

Williams, M. (18 June, 2018). Cementless fly ash binder makes concrete ‘green’. Retrieved 1 February, 2019, from Rice University News & Media: http://news.rice.edu/2018/06/18/cementless-fly-ash-binder-makes-concrete-green-2/


*edited on 6th April 2019