China produces and consumes about 60 percent of the world's cement -- the Three Gorges Dam alone required 16 million tonnes of it. To put China's massive 21st century construction splurge and concrete consumption into perspective, Bill Gates made a mind-blowing comparison.
According to his blog, between 2011 and 2013, China consumed 6.6 gigatons of concrete - that's more than the U.S. used in the entire 20th century. Look at what the U.S. built between 1901 and 2000: all those skyscrapers, the Interstate, the Hoover Dam, the list goes on and on but all that concrete only amounted to 4.5 gigatons.
*Click below to enlarge (charted by Statista)
This month I reviewed a book about materials by my favorite author, Vaclav Smil. If you remember just one thing from the review, it would probably be this infographic, which captures what Smil calls the most stunning statistic in his book:
One of the big problems with putting down so much concrete is that it deteriorates. In the coming decades, the United States and China alone will need to spend trillions of dollars replacing and disposing of concrete laid down in the past generation. There are also environmental problems, including all the carbon dioxide that’s released during production.
But it’s important to remember concrete’s benefits too. Smil cites studies that say replacing mud floors with concrete floors in the world’s poorest homes would improve sanitation and cut the incidence of parasitic diseases by nearly 80 percent. Paving streets, he says, “boosts land and rental values, school enrollment, and overall economic activity and also improves access to credit.”
I am optimistic that innovation can help reduce the downsides of concrete. For example, mini-sensors embedded inside it could alert engineers when it needs to be replaced. And researchers are developing new materials that would cut down on our need for concrete in the first place.
So concrete is a complex topic, and as usual Smil does a great job educating you about it.