Article Name: The problem with reinforced concrete
Author: Guy Keulemans, Associate Lecturer, UNSW, Australia
Source: TheConversation.com (Click for full article)
Publication Date: June 17, 2016
Quick Summary: Reinforced concrete is bad, mm-kay?
Keulemans' basic argument is this: As a society, we will have to spend "trillions of dollars" to repair and replace modern reinforced concrete structures. Why? Concrete by itself is a pretty durable material (as evidenced by the Pantheon in Rome, for example). But when you add in steel reinforcement -- which began in the 19th century -- there's the problem. Steel rusts. Concrete allows water to permeate, which just furthers the rust problem. Basically, while early engineers thought that steel reinforced concrete structures would last "perhaps 1,000 years," in reality, "deterioration can begin in as little as 10 years." Throw in the well-documented environmental impacts of cement production -- responsible for "roughly 5% of global CO2 emissions" -- and Keulemans argues that the total costs associated with reinforced concrete -- replacement, repair and indirect environmental -- are tremendous.
Interestingly -- and refreshingly -- though, the author's ultimate conclusion is not that we should abandon steel reinforcement, at least not immediately. Instead, Keulemans points to a need for further research and development into understanding the "vibrant" nature of reinforced concrete. Alternative materials, organically neutral additives and corrosion inhibitors, and other potential developments could mitigate the purported issues facing steel reinforced concrete.
However, there are alternatives even today: Hot-dipped galvanized steel, and stainless steel are just two examples. Perhaps the problem is not that there aren't solutions available. Rather, the real issue may be the unwillingness by specifiers and purchasers to look beyond today's budget cycles and build for the long-term.
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