We proudly present our first experiment in rapid liquid 3d printing of concrete (RLPC). This method makes possible 1) any shape from concrete to be printed 2) rapidly and 3) lets it reach maximum strength not being negativelly affected by too fast dehydration. In essence, the method is very similar to the rapid liquid 3d printing of polyurethanes, invented in MIT in 2017 (https://selfassemblylab.mit.edu/rapid-liquid-printing).
RLPC appears to be ideal for concrete, because does not require toxic, or specially designed proprietary components (gels or suspensions). The object upon printing is immersed in humid media, that is more optimal for hardening of concrete, than the air in a "standard" process of liquid deposition (LDM). One uses affordable and easily available materials: usual clay or retarded mortar as the matrix, and normal mortar paste (that turns into concrete upon hardening) for the printed object.