Investigating the Effect of Different Parameters on Physical Properties of Metakaolin-Based Geopolymers

Abstract

Recently, geopolymers have received widespread attention due to their ability to completely replace ordinary cement with better efficiency, lower cost, and less damage to the climatic environment. This paper aimed to prepare MK-based geopolymer cement at ambient temperature with different alkaline activators and processing parameters. XRD, PSA, DTA-TGA, SEM, and other techniques have characterized the prepared samples. ANOVA test was employed to identify the main effect of the processing parameters. Results showed that the incorporation of potassium ions has a negative effect on the physical properties of GP, in which the presence of such ions tends to decrease the density of GP. Furthermore, the apparent porosity and water absorption were increased. For Na and K, Na-activated GP, it was also concluded that the density of GP increases by increasing Si/Al ratios. Despite the Na-based GP processes having a larger density in compared to the K, Na-based ones. The results also suggested a strong effect of the W\MK ratio on physical properties, in which decreasing this ratio is necessary to achieve GP with better properties. The findings also revealed that a one-minute mixing period was sufficient for producing a homogeneous and dense GP paste.

Keywords

• geopolymer
• sodium
• potassium
• physical properties
• anova