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We need to stop using concrete as a building material: there are enormous numbers of alternatives and the vast majority of them use a fraction of the carbon dur
by hkt 3y ago
We need to stop using concrete as a building material: there are enormous numbers of alternatives and the vast majority of them use a fraction of the carbon during their lifecycles.
For instance, lime stabilised soil has been used in large civil engineering projects for decades. Lime has been used as a render and a cement for thousands of years and if extracted from limestone sensibly minimises emissions to a fraction of those from concrete.
(This post written from the Centre for Alternative Technology, on lunch while I am on a course learning how to build houses out of load bearing straw bales)
- quickthrower2 3y agoThe one in Wales? Went there as a kid. Loved it.
- hkt 3y agoThat's the one. They do residential courses. Also a variety of masters degrees.
- zeotroph 3y agoAlso Compressed earth blocks, which use only very little cement, should be used more. Or Cross laminated timber, great for long-term sequestering of carbon. https://en.wikipedia.org/wiki/Compressed_earth_block https://en.wikipedia.org/wiki/Compressed_earth_block https://en.wikipedia.org/wiki/Cross-laminated_timber https://en.wikipedia.org/wiki/Cross-laminated_timber
- wiredfool 3y agoLime isn't really all that different from cement -- it's made by baking the CO2 out of limestone, historically using charcoal kilns (also not very CO2 friendly).
- pfdietz 3y agoThere's a company commercializing lime obtained from silicates. The process involves acid dissolution of the silicate, then conversion of the chlorides to oxides by high temperature reaction with steam (releasing the chlorine in hydrogen chloride, which is then recycled back to dissolve more silicates.)
- SoftTalker 3y agoAnd how do they create the steam?
- pfdietz 3y agoThat wasn't specified. It can be done without fossil fuels, of course. If I understand correctly, it doesn't require more heat energy than the conventional process starting from limestone.