Geopolymer-based concrete to reduce carbon footprint of construction industry
, 2013, Vol. 65, No. 12, pp. 57-62
Akbari, H.; Heller, T.; Shin, S.; Yang, X.; Kolay, P.; Kumar, S.; Mohanty, M.K.
Ordinary portland cement (OPC) is the key pozzalonic component of the concrete mix widely used as a construction material worldwide. Billions of tons of OPC are used in the construction industry each year. However, calcinations of limestone and silica that produce OPC also produce almost an equal amount of CO2 during the cement manufacturing process. Thus, OPC production accounts for nearly 7% of all anthropogenic CO2 emissions each year. The main objective of this study was to develop a geopolymer-based composite to be used as a substitute for OPC in concrete application to significantly lower the carbon footprint of the construction industry. A waste material produced during the coal combustion process was used as the main raw material for the geopolymer-based composite. It was mostly the nonmetallic content of the F-type fly ash produced from the combustion of bituminous coal. The authors envisioned extracting some of the valuable metal oxides from fly ash prior to using the major nonmetallic portion of the fly ash for geopolymer concrete application. The results obtained from this study showed that the compressive strength of geopolymer concrete compares favorably with that of conventional concrete prepared using OPC.