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Can We Live Without Concrete? (cnn.com)
A combination of cement, water and ground rock or sand, on the surface concrete might seem crushingly mundane. Yet it has defined construction in recent centuries and with it, in part, modernity. From a report: But do we need to re-evaluate our concrete habit for our sakes and the planet's? Production of cement is disastrous for our biosphere, while the degradation of many concrete buildings has some construction experts predicting a colossal headache in the future. There are myriad proposed solutions, such as changing the way we make concrete, creating sustainable alternatives or doing away with it altogether. But would we want to live in a world without concrete? And what would that world look like?
"We make more concrete than anything else, any other product, apart from clean water," says Paul Fennell, professor of clean energy at Imperial College London. One 2015 report estimates that each year approximately three tons of concrete are used for every person on Earth -- roughly, 22 billion tons. To put that in context, a recent study estimated that 8.3 billion metric tons of plastic have been produced, ever. Manufacturing cement, concrete's binding agent, is energy-intensive, Fennell says. Ordinary Portland cement -- the most common form in concrete -- is produced by baking lime in a kiln and emits approximately one ton of carbon dioxide for every ton of cement. Concrete production is responsible for approximately 5% of global man-made CO2 emissions, according to the World Business Council for Sustainable Development.
"We make more concrete than anything else, any other product, apart from clean water," says Paul Fennell, professor of clean energy at Imperial College London. One 2015 report estimates that each year approximately three tons of concrete are used for every person on Earth -- roughly, 22 billion tons. To put that in context, a recent study estimated that 8.3 billion metric tons of plastic have been produced, ever. Manufacturing cement, concrete's binding agent, is energy-intensive, Fennell says. Ordinary Portland cement -- the most common form in concrete -- is produced by baking lime in a kiln and emits approximately one ton of carbon dioxide for every ton of cement. Concrete production is responsible for approximately 5% of global man-made CO2 emissions, according to the World Business Council for Sustainable Development.
They are starting to build wooden skyscrapers http://www.bbc.com/future/stor...
"The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
They compared concrete to plastic, but most of the weight (about 85%) in concrete is sand and rock. Although even with that the world uses a lot of cement.
Rather than looking for alternatives I'm guessing this is a plea to make the manufacture of cement more environmentally friendly (green energy for the heat, capture the CO2, etc.). That would make far more sense than trying to find an alternative to concrete.
If we could teach AI to quarry, transport, shape and stack rocks at least as well as humans did in the 17th century, we could literally build castles (and bridges and aquaducts) with very little energy input. Rocks are everywhere, and an army of AI powered instruments could be programmed to improve on the work of even the best stonemasons: If they scanned each available stone that comes from a quarry, algorithms could design the optimal stacking arrangements to minimize gaps and maximize structure stability. They could "solve" a construction project like it's a giant 3D puzzle, thus minimizing the number of stones that would need to be chiseled. But even chiseling stone with machines uses very little energy. The pace of construction would only be limited by the number of autonomous tools brought to bear, and they themselves could turn out to be cheap and mass-producible. Sure, you can't build skyscrapers from rocks, but I would happily live in a city of six story rowhouse blocks built from stone. The neighborhoods in Europe that are actually built in this way are beautiful, functional and pleasant to live in. With AI building tools that sink the cost of labor to almost zero, I think we should explore returning to some of these old, well-tested building methods and architectural designs.