Minimising the global warming potential of clay based geopolymers

Production of Portland cement (PC) binders contributes substantially to global CO2 production and various bodies including the Intergovernmental Panel on Climate Change (IPCC) have identified geopolymers as alternative binders with the potential to reduce these emissions. The hypothesis of this research is to investigate whether this is a realistic proposition in the light of limited waste materials such as fly ash and ground granulated blast furnace slag commonly used as geopolymer precursors. The effect of use of natural clay minerals as alternative precursors on global warming potential (GWP) is investigated. Methods of designing mixes with the lowest possible GWP are presented and these are compared to the GWP of PC and currently available metakaolin based geopolymer binders. It is concluded that it is possible to reduce the GWP by approximately 40%, but other impacts may increase.

[1]  Steve Goodhew,et al.  The potential for using geopolymer concrete in the UK , 2013 .

[2]  Erich D. Rodríguez,et al.  Mechanical and thermal characterisation of geopolymers based on silicate-activated metakaolin/slag blends , 2011, Journal of Materials Science.

[3]  Martin Schneider,et al.  Sustainable cement production—present and future , 2011 .

[4]  C. Kaps,et al.  Effect of thermal pre-treatment conditions of common clays on the performance of clay-based geopolymeric binders , 2013 .

[5]  Leenard Baas,et al.  Improving the CO2 performance of cement, part I: utilizing life-cycle assessment and key performance indicators to assess development within the cement industry , 2015 .

[6]  H. V. Oss.  SLAG—IRON AND STEEL , 2002 .

[7]  J. Deventer,et al.  Understanding the relationship between geopolymer composition, microstructure and mechanical properties , 2005 .

[8]  J. Davidovits.  Geopolymer chemistry and applications , 2008 .

[9]  R. Greenwood,et al.  The zeta potential of kaolin suspensions measured by electrophoresis and electroacoustics , 2007 .

[10]  C. Flachsland.  Mitigation of Climate Change: Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change , 2015 .

[11]  Pre De Silva,et al.  Medium-term phase stability of Na2O–Al2O3–SiO2–H2O geopolymer systems , 2008 .

[12]  Hua Xu,et al.  The effect of alkali metals on the formation of geopolymeric gels from alkali-feldspars , 2003 .

[13]  G. Corder,et al.  Costs and carbon emissions for geopolymer pastes in comparison to ordinary portland cement , 2011 .

[14]  M. Ahmaruzzaman,et al.  A review on the utilization of fly ash , 2010 .

[15]  Matthias Fawer,et al.  Life cycle inventories for the production of sodium silicates , 1999 .

[16]  V. Sirivivatnanon,et al.  Kinetics of geopolymerization: Role of Al2O3 and SiO2 , 2007 .

[17]  A. Buchwald,et al.  The suitability of thermally activated illite/smectite clay as raw material for geopolymer binders , 2009 .

[18]  J. Deventer,et al.  Geopolymer technology: the current state of the art , 2007 .

[19]  B. Metz,et al.  Climate change 2007 : mitigation of climate change :contribution of Working Group III to the Fourth assessmentreport of the Intergovernmental Panel on Climate Change , 2007 .

[20]  Chai Jaturapitakkul,et al.  Effect of fly ash fineness on compressive strength and pore size of blended cement paste , 2005 .

[21]  Martyn Jones,et al.  Fly Ash Route to Low Embodied CO2 and Implications for Concrete Construction , 2011 .

[22]  Fernando Pacheco-Torgal,et al.  Composition, strength and workability of alkali-activated metakaolin based mortars , 2011 .

[23]  S. Chandrasekhar.  Influence of Metakaolinization Temperature on the Formation of Zeolite 4A from Kaolin , 1996, Clay Minerals.

[24]  J. Madejová,et al.  Reaction of smectites with iron in aerobic conditions at 75 °C , 2013 .

[25]  Martijn Gough.  Climate change , 2009, Canadian Medical Association Journal.

[26]  Keun-Hyeok Yang,et al.  Assessment of CO2 reduction of alkali-activated concrete , 2013 .

[27]  N. Roussel,et al.  An environmental evaluation of geopolymer based concrete production: reviewing current research trends , 2011 .

[28]  Sunkuk Kim,et al.  Energy-efficient algorithms of the steam curing for the in situ production of precast concrete members , 2013 .

[29]  Corinne Le Quéré,et al.  Climate Change 2013: The Physical Science Basis , 2013 .

[30]  Pavel Rovnaník,et al.  Effect of curing temperature on the development of hard structure of metakaolin-based geopolymer , 2010 .