The pioneering work done by Karen Scrivener at EPFL on LC3 has generated huge interest in using calcined clay as and SCM to reduce the per ton carbon emission of cement. Of course, calcination is a thermal process and uses plenty of energy, so calcined clay can have a significant carbon footprint of its own, albeit much less than clinker.

If clay could be activated mechanically rather than with heat, the energy required and carbon emitted would be much less.