SpaceCrete 2.0: Pumping 13' concrete walls without forming - lower cost for a net-zero passive home

https://spacecrete.com/ Please see our more recent videos! SpaceCrete 2.0 is an EXPERIMENT with our OLD 3D-Admix - the first real building done with the new method, where we pump concrete walls but without forming them - just stack the concrete and use a guided screed that lets us vibrate it when needed. We inject thickening admixture and accelerator into the pump line around 10' to 15' from the end, so that the concrete will stack to make the walls - 4" thick in this case. We are still learning the method and have made improvements to mix design and hardware since this project. For this building all the concrete is thermally isolated from the exterior and the earth, so all the thermal mass is all in conditioned space where it belongs. This method will really lower the cost of net-zero energy homes, and it avoids all wood or other decay-able materials for the exterior walls. This is for more-affordable permanent passive-design homes - that can also be fireproof. The admixture-injection method will create a 3D-printable mix with (lower cost) concrete you can order from a batch plant. We can stack the layers vertically against foam panels as fast as the concrete pump moves the material - and have fun doing it! Now several months later these walls are showing no cracking of any type. It took a bit of testing to get a rich mix like this, that is exposed to the elements while plastic and while curing, to not have any shrinkage. On this first full-scale test, the shrinkage control mechanisms worked better than we expected. Zero cracks! Our previous video shows a mix more appropriate for numerically-controlled 3D-printing, in that it can stack very rapidly and it pumps more easily. The trade off is that the previous mix has some shrinkage. We are now working on combining the best attributes of both mixes - very easy very rapid pumping and stacking with zero shrinkage. A special thanks to La Rumba of Australia for letting us use their music. Hope you like it!    • La Rumba - Pena Penita