Concrete

The single building material most ubiquitous in today’s built environment is undoubtedly Portland cement concrete. Since the discovery of the benefits of concrete-like building materials in the Near East as early as 6500 BC,[1] concrete has become so widespread as to be the second most widely-produced product in the world (after clean water)[2] for a variety of reasons. However, architects of today and of the future must look beyond Portland cement concrete as they seek building materials.

The production of Portland cement, the binding agent used in most concrete, results in the release into the atmosphere of nearly a ton of CO2 for every ton of cement produced.[3] Even after production of cement, the chemical reactions that make concrete such a desirable building material produce a very undesirable side effect: tons of carbon dioxide. Annually, around 5% of global CO2 emissions are a result of the concrete industry;[4] that’s roughly the same amount as is produced by all cars, trucks, planes, trains, boats, and other forms of transportation in the USA,[5] but most people have never thought of concrete as unsustainable. As increasing amounts of greenhouse gases accumulating in the atmosphere alter the global climate, architects and builders are being forced to reconsider this material.

 

References:

[1]  Gromicko, Nick, and Kenton Shepard. “The Herstory of Concrete.” InterNACHI, International Association Of Certified Home Inspectors, http://www.nachi.org/herstory-of-concrete.htm.

[2] Brownell, Blaine. “Course Introduction.” Material Transformations. 5 Sept. 2018, Minneapolis, Ralph Rapson Hall Room 45.

[3] “Can the Building Industry Break Its Addiction to Concrete?” CNN, Cable News Network, 4 May 2018, http://www.cnn.com/style/article/concrete-alternatives-future-building/index.html.

[4] “The Cement Sustainability Initiative: Our Agenda for Action,” World Business Council for Sustainable Development, 1 June 2002.

[5] “Sources of Greenhouse Gas Emissions.” EPA, Environmental Protection Agency, 11 Apr. 2018, http://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions.

Image Credit: Sarah Briggs-Ramsey. http://www.postwarconcretepostscript.com/about-the-project/