Carbon footprint of geopolymeric mortar: study of the contribution of the alkaline activating solution and assessment of an alternative route

• Published in: RSC advances 2014, Vol.4 (45), p.23846-23852
• Main Authors: Mellado, A., Catalán, C., Bouzón, N., Borrachero, M. V., Monzó, J. M., Payá, J.
• Format: Article
• Language: English
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C4RA03375B

CO 2 emissions associated with geopolymeric mortar prepared using spent fluid catalytic cracking catalyst (FCC) were compared to those calculated for plain ordinary Portland cement (OPC) mortar. Commercial waterglass used for preparing the alkaline activating solution for geopolymeric mortar was the main contributing component related to CO 2 emission. An alternative route for formulating alkaline activating solution in the preparation of the geopolymeric binder was proposed: refluxing of rice husk ash (RHA) in NaOH solution. Geopolymeric mortar using rice hull ash-derived waterglass led to reduced CO 2 emission by 63% compared to the OPC mortar. The new alternative route led to a 50% reduction in CO 2 emission compared to geopolymer prepared with commercial waterglass. Replacement of commercial waterglass by rice hull ash-derived waterglass in the preparation of the geopolymer did not cause a significant decrease in the mechanical strength of the mortar. CO 2 intensity performance indicators ( C i ) for geopolymeric mortars were lower than that found for OPC mortar, indicating that the new route for activating solution led to the lowest C i value.