Can we live without concrete – slashdot gas city indiana restaurants


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.

Some applications of concrete are frivolous and I think can be replaced. The reason is mostly cost and availability, and the current labor force is skilled with using it. The wall-facade material of choice before concrete, and before gypsum drywall, was Lime plaster. For wet or exterior applications I am in favor of using lime as it is less carbon-intensive than concrete and produces a beautiful lighting effect from birefringence (, owing to the tiny calcite crystals that form when it cures back into limestone. See for an example.

Producing Lime plaster is less carbon-intensive than cement as it requires lower temperatures, and the CO2 driven off by the limestone during calcining (which happens in Ordinary Portland Cement production as well) is mostly re-absorbed by the slaked lime as it cures back into limestone (leaving the net CO2 footprint coming from the fuel used to calcine the lime, if coal or natural gas or wood is used, although perhaps decades into the future someone comes up with a nuclear-fueled kiln, electric or high temp gas or whatever).

The big downside to lime plaster is the time it takes to cure, and what that does for timelines and labor costs. It usually requires multiple thin coats (with a week or more between =3/8 inch coats – need time for CO2 to reabsorb as carbonic acid which also requires the material be damp, but not covered in water) which blows up the labor costs.

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.

There is a mythconception touted by some that concrete is bad. That is totally wrong. Concrete is almost all rock and sand. There is very little cement (the material at issue) in it. And the long term net effect is that concrete is a benefit because concrete structures last for a very long time, measured in hundreds to thousands of years as opposed to wood built structures that last mere decades.

Additionally, if you properly design your structures you can make concrete even greener by eliminating the need to heat or cool the buildings. I have done this with both our home and our butcher shop. Concrete offers tremendous thermal mass which can store the heat from summer over to winter to keep the building warm and store the cold from winter over to summer to keep the building cool.

I have done this with our home which masses about 100,000 lbs inside an insulated envelope. Even in our extreme cold climate in the central mountains of northern Vermont we don’t have to heat or cool our house. It will stay in the mid-40’s through the winter and rise to the 60’s in the summers. We can optionally raise that to the mid-70’s in the winter with just 0.75 cord of wood (a very small amount for those of you who don’t use wood heat), which is a renewable resource from dead wood on our land.

Our butcher shop is built along the same lines but far more massive at 1.6 million pounds of concrete built in six shells with insulation between each. We have no heating system and no refrigeration system to chill our cutting room, etc. We’ve been operating for three years under Vermont state inspection and on May 1st we received our USDA license. I’ve been told repeatedly by the USDA and other government officials that they are amazed by our facility because it is so good, requires so little maintenance, is so easily cleaned and how it naturally stays the right temperatures. All of that is about design. I love math. Math applied is even better – it solves real problems.