A comparative analysis between the embodied energies of ordinary Portland cement and coal fly/coal bottom ash blend geopolymer by adopting life cycle assessment framework

• Main Authors: Ong, Marielle Clarisse S., Rapon, Sharah Mae
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Polymer-impregnated concrete > Environmental testing; Portland cement > Environmental testing; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/14928
• Institution: De La Salle University

The demand for production of concrete has been consequently growing that the amount of energy it consumes result to significant emissions of greenhouse gases. In order to improve the environmental impact of concrete production, geopolymers have been identified as an alternative product. However, some studies have shown that geopolymers have higher environmental impact compared to OPC considering other impact categories such as producing waste materials. This study compares the embodied energy of OPC concrete with geopolymer concrete by performing emergy analysis within the LCA framework. Furthermore, uncertainty analysis via Monte Carlo simulation (MCS) is implemented to account for data tolerances and uncertainties. A functional unit of 1m3 was used for both OPC and geopolymer concrete having a parameter of 28-day compressive strength of 33-35 MPA.Results of emergy analysis showed that geopolymer concrete has an emergy value of 8.11 x 1015± 4.16 x 1014 sej/m3 whereas OPC concrete resulted in an emergy value of 6.89 x 1015 ± 3.51 x 1014 sej/m3. The embodied energy of OPC concrete is comparable with geopolymer concrete especially when the embodied energy for OPC concrete will reach the highest value at 2.63 x 1015 sej/m3. Values showed that the embodied energy of geopolymer is higher by 18.40% as compared to OPC due to the amount of sodium silicate used for the production of geopolymer concrete. In terms of the greenhouse gas emission (GHG), the carbon dioxide emission for geopolymer is around 720 MT of CO2 eq./m3 while OPC has a carbon emission of 3009.50 MT of CO2 eq./m3. This shows that the GHG emission of OPC is approximately four times higher than that of the emission of geopolymer. Furthermore, Monte Carlo simulation was also conducted for the comparison of carbon dioxide emission. This study recommends future researches to ask for the participation of industry for inventory analysis so as to obtain a sufficient and complete data.