Magnesium Based Cements
There is a whole class of cement that was very popular in the days before the invention and manufacture of Portland cement quickly replaced its use. Generally classified as magnesium-based cement, this material was used in historic times, dating back to ancient times in Europe, India, and China, among other countries. The Great Wall of China and many of the stupas in India, still standing today, were all made with magnesium-based cements. It is unfortunate that Portland cement has replaced the use of these magnesium products because there are many ways in which they are superior. Primary among these is the fact that they require much less energy to produce and do not off-gas as much CO2 as Portland cement in their manufacture. The phosphates typically used to combine with the magnesium can even be sourced from animal wastes or fermented plants. Add to this fact that these ...