Preparation and Mechanical Properties of Potassium Metakaolin Based Geopolymer Paste

Abstract:

In this study, geopolymer samples were prepared by mixing metakaolin (MA) with activator solution made of potassium alkali silicate solution, potassium hydroxide flakes, and additional water. The aim of the experiment is to evaluate the mechanical strength of hardened samples based on four test variables including the SiO₂/K₂O molar ratios, K₂O concentration, H₂O/MA water coefficient, and curing temperature. The results reveal that K₂O concentration and H₂O/MA water coefficient impact strongly on the compressive strength, whereas varying of SiO₂/K₂O molar ratios in the range from 1.0 – 1.4 does not significantly change the compressive strength of geopolymer samples. On the other hand, high-temperature curing leads to higher mechanical strength of the samples in the early-age compared to curing at room temperature, due to the faster establishment of hard structure in the early-age of geo-polymerization process. However, curing at a temperature range of 80°C – 100°C contributes the non-linear strength development of the samples over the time.

• Periodical: Advanced Engineering Forum (Volume 31)
• Pages: 38-45
• DOI: https://doi.org/10.4028/www.scientific.net/AEF.31.38
• Online since: February 2019
• Authors: Hiep Le Chi, Petr Louda, Totka Bakalova, Vladimír Kovačič
• Keywords: Curing Temperature, H₂O/MA Water Coefficient, K₂O Concentration, Mechanical Strength, Metakaolin Based Geopolymer, SiO₂/K₂O Modul

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