A new type or cement is made from raw materials that are typically used to make ordinary Portland cement (OPC) clinker.The kiln feed raw mix proportions are adjusted so as to produce a clinker rich in low-lime calcium silicate phases such as CS and C3S2 instead of the high-lime phases C3S and C2S typical of OPC.Production of such clinker requires 30% less limestone compared to OPC clinker and allows sintering at temperature as low as 1200℃ compared to 1450℃ for OPC.The clinker is ground to make a cement of similar fineness to OPC, and its total manufacturing CO2 emissions are estimated to be 30% less than for OPC.This cement does not harden by hydration;rather, it hardens by carbonation.Its main carbonation products are CaCO3 and SiO2.The CaCO3 is primarily formed as calcite with some vaterite.The SiO2 is present in a non-crystalline form.Microstructural evaluation shows that silicon is less mobile then calcium during curing and remains around the cement particles.However, the CaCO3 precipitates in the pore spaces of the cement matrix.This cement is a patented cement of Solidia Technologies and is commercially available as Solidia Cement TM.