Large scale 3D printing

[ai_vin]

I wonder if they could do it with something other than concrete? Globally, the making of cement is responsible for 7-10% of our CO2 emissions. Climate change is real and anything we can do to slow it down would be helpfull. Maybe they could use a geopolymer as the binder, or make the cement with a process like S.T.E.P. (Solar Thermal Electrochemical Production): Solar thermal heat (not fossil fuel heat) melts the limestone which then undergoes an electrolysis process that reduces the carbon dioxide (adds electrons) to produce only lime, oxygen, and graphite which can be readily stored as solid carbon. As an added plus lime will recarbonate as it cures by taking CO2 out of the air so in use the houses become net carbon sinks if the original carbon is stored as graphite.