Effect of ZrO_2 and MgO Addition on Structure, Mechanical and Thermal Properties of Metakaolin-Based Geopolymer Composites

摘要

This research studies the fabrication and properties of reinforced-geopolymer composites for Green Building. The study comprises of phase formation, microstructure, mechanical and thermal properties. Metakaolin-based geopolymer has been fabricated from calcined kaolin at 750 °C for 6 h. Sodium hydroxide solution with 10 M and sodium silicate solution were used as alkaline activators. The ratio between metakaolin and solution was 1:1.25. Two reinforcements; Zr02 and MgO at the composition of 0, 1, 3, 5, 7 and 9 wt% were added, then well-mixed together. After casting in acrylic mold, samples were cured at 50 °C for 72 h and then stored in air for 7 and 28 Days. Phase formation, microstructure, compressive strength and thermal conductivity were determined by XRD, SEM, universal testing and thermal conductivity measurement, respectively. The results revealed that after stored for 28 Days, XRD patterns of geopolymer with and without reinforcements show typical amorphous characteristic. Microstructure observation revealed the dense and heterogenous. The addition both of reinforcements has no effect on the geopolymerization reaction. Compressive strength tends to increase with increasing the amount of MgO content. Moreover, thermal conductivity slightly increased with the amounts of Zr02 and MgO increase.