Abstract—Geopolymers are new types of materials which can be synthesized by various natural materials or by-products as source material. Fly ash is a type of by-product can be used in the synthesis. Source materials are activated by alkaline solutions and silicate solutions. In this experimental study, fly ash was used for geopolymerisation. By this way, most generated by-product was converted to valuable product. As an activator solution, 4M sodium hydroxide and sodium silicate were used. Alkaline solution was selected in low molarity because of the corrosive effect of hydroxide solution. The geopolymer pastes cured at 120°C for 6h, 15h and 24 hours. X-ray Diffraction Spectroscopy and Scanning Electron Microscopy techniques were used to investigate the structure of the samples. As a result of analysis, geopolymeric structure was obtained by this synthesis conditions. It was found that the higher compressive strength values can be obtained with higher molarities if desired for applications like building materials. Also some fillers may be added to increase the compressive strength values. Test results have also revealed that the compressive strengths increased with increasing curing duration.
Index Terms—Geopolymer, activation, mechanical properties, microstructural properties.
E. Arioz and Ö. M. Koçkar are with the Department of Chemical Engineering, Faculty of Engineering and Architecture, Anadolu University, Eskişehir, Turkey (e-mail: mkockar@anadolu.edu.tr).
Ö. Arioz is with the Department of Civil Engineering, Faculty of Engineering and Architecture, Anadolu University, Eskişehir, Turkey (e-mail: oarioz@anadolu. edu.tr).
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Cite: E. Arioz, Ö. Arioz, and Ö. M. Koçkar, "Mechanical and Microstructural Properties of Fly Ash Based Geopolymers," International Journal of Chemical Engineering and Applications vol. 4, no. 6, pp. 397-400, 2013.
