News Detail

Concrete: The Most Destructive Material on Earth?

6/3/2019

Come on, you have to be kidding

I understand from ACI Executive Vice President Ron Burg that an article from the newspaper the Guardian¹ circulated among the membership of ACI's Strategic Development Council (SDC) at its meeting in San Diego, CA, in February. The article's headline and content were not flattering to our industry. The article argued that although water is the most used material on earth ahead of concrete, concrete is the most destructive material.

While the article does provide a few basic facts about cement and concrete construction, such as the fact that China now consumes 50% of the cement production in the world, its basic premise conflates carbon output and greenhouse gases with economic, political, and social issues in selected countries around the world. It is worth noting that this type of attack on the concrete industry and its relative position in the "green" landscape represents an uphill battle for us.

As an industry, we must recognize the reality that concrete will never be known as a carbon-neutral material unless there is a revolutionary breakthrough resulting in complete elimination of carbon dioxide and other gas emissions during cement production. The fact is that production, use, and disposal of any type of construction material results in carbon dioxide emissions.²

What is missing from this attack on the concrete industry is the recognition of the permanence, resiliency, and durability of concrete construction and the significant steps that have been taken to demonstrate its sustainability. ACI Committee 130, Sustainability of Concrete, recently issued "Report on the Role of Materials in Sustainable Concrete Construction (ACI 130R-19)," a report that provides an excellent, fair, and balanced discussion about cement manufacturing and the production of greenhouse gases relative to other industrial sectors in the United States. The fact is that the cement industry is at the lower end of the spectrum when compared to the oil, gas, and chemical industries. Moreover, it should be noted that the amount of energy used in the production of cement today is about 40% lower than the amount used 40 years ago.

What is completely missing in the premise of the article about concrete being the most destructive material on earth is the inherent value provided by concrete, the utility of the structures it forms, its long-term durability, and the service provided over the life of the structure. There is no doubt that environmental and economic analyses must be carried out as part of evaluating a construction project and selecting the materials to be incorporated for sustainability considerations.

The article from the Guardian completely misses the point. By only considering the cost of cement production in terms of energy use and greenhouse gases emitted as the metric for what is considered destructive, it leads to an erroneous conclusion about concrete. The analysis of service life, durability, and resiliency offered by concrete in the structures that are built is ignored.

As presented in the new report from ACI Committee 130, these other factors must be considered to provide a fair and balanced view of sustainability. It is worth noting that ACI 318-14 (and ACI 318-19), "Structural Concrete Building Code," in Section 4.9, provides that sustainability requirements can be used in design in addition to the strength, serviceability, and durability requirements of the Code.

So, in my opinion, the article in The Guardian in the context of meaningful journalism about concrete is completely irrelevant. However, it should point out to us in the concrete industry a cautionary tale of how perceptions, whether true or not, can be shaped by printed words.

Randall W. Poston

1. www.theguardian.com/cities/2019/feb/25/concrete-the-most-destructive-material-on-earth.

2. www.iisd.org/library/emission-omissions.