Calcium Carbonate Cement Essay

Calcium Carbonate Cement

The material:

Calcium carbonate cement is a material that is made up of carbon dioxide (CO2) that has been converted to carbonate (CO3) and bound to minerals such as calcium and magnesium. It is a white powder-like material that can be used as an aggregate or supplementary cementitious material in construction and could substitute Portland cement.

The Concept:

The process of making calcium carbonate cement was developed by studying the formational process of coral reefs and utilising the principles at work. According to David Biello (2008), when constructing their shells and reefs, coral takes calcium and magnesium from seawater and combines them with CO2 to form calcium carbonate, a solid material, at normal temperatures

Drawing inspiration from the construction process of coral, Constanz developed a process that dissolves CO2 in seawater to produce calcium carbonate.

Constanz established a company called Calera, which is now developing and marketing this new technology. The company has already set up a pilot plant at Moss Landing power plant in California’s Monterrey Bay that creates calcium carbonate from the waste CO2 emitted by the power plant.

“Every ton of cement replacement produced by Calera avoids the release of approximately one ton of carbon dioxide that would otherwise be emitted by the traditional manufacturing of Portland cement.” (Meinhold, 2011)

The process: The process whereby Calera reduces CO2, harnesses the CO2 gas emitting from industrial sources. The CO2 is then converted to a new calcium carbonate cement system which is then used to produce an assortment of valuable products. The manufacturing of building materials made from this novel cement system is Calera’s main focus. According to Calera (2015), without having to be concentrated, CO2 can be captured from the emitting sources by Calera’s process and then converted into the solid material calcium carbonate, permanently trapping and isolating the

In order to reduce the carbon footprint of traditional concrete, the environmentally sustainable calcium carbonate can function as a supplementary cementitous material and substitute a portion of the Portland cement. The calcium carbonate can also completely replace the cement and become the main binder system in concrete products. Products like magnesium oxide, gypsum, calcium silicate and Portland cement have been replaced by this unique binder in the wallboard and cement board products produced by Calera. (Calera, 2015)

Several projects made use of Calera’s calcium carbonate as a supplementary cementitous material, including sidewalks and flatwork in an office building, and replaced about 15% of Portland cement used in the concrete mixture.

“We have demonstrated the ability to make a variety of decorative concrete products such as countertops, plant holders and benches. The products contain traditional sand and aggregate all held together in a concrete mix by the calcium carbonate cement.” (Calera, 2015)

Future: