Although we’ve heard a lot about how 3D-printing concrete homes speeds up the construction process, you still have to wait up to 28 days for the concrete to sufficiently cure. A new printable substitute, however, is ready to go in just three days.

Concrete consists of three parts: water, an aggregate such as sand or gravel, and a cement which binds everything together. The cement is the part that typically takes about a month to cure after being poured. And a slow curing time isn’t cement’s only problem.

Traditional Portland-style cement is made by grinding up limestone and other raw materials, then heating the resulting powder to temperatures of up to 1,450 ºC (2,642 ºF). Unfortunately, the processes by which that heat is generated produce a lot of carbon dioxide.