Study of the Curing Temperature of 600°C, 700°C and 800°C of Mouyondzi Clay on the Mechanical, Physical and Microstructural Properties of Geopolymer Obtained

Abstract

This work consists of determining the right curing temperature for Mouyondzi clay, with a view to obtaining a very reactive metakaolinic amorphous phase, which will give us a geopolymer with good physical and mechanical performance. The kaolin-dominant Mouyondzi clay was calcined at 600℃, 700℃ and 800℃ with a heating rate of one degree per minute. In order to achieve the objective of this work, the performance of geopolymer was measured by compressive strength on geopolymer prisms of 28 days of age, by XRD and IRFT of geopolymer powders, calcined clay and raw clay, and by SEM of geopolymer blocks. Analysis of the results shows that the resistance value increases with the curing temperature of the clay and reaches a maximum of 49 MPa at 800℃. At 600℃ we already have 31 MPa, the equivalent of Portland cement with the addition. The XRD confirms the disappearance of clay species from 600℃. At 800℃ there is not yet the appearance of a new crystalline phase. Quartz is the only mineral species present. We can therefore confirm that at 800℃, the geopolymer obtained exhibits higher physical and mechanical performance than the other curing temperatures studied for Mouyondzi clay. This is confirmed by the appearance of a new aluminosilicate phase in the IRFT spectra and in the SEM images appearing as a continuous plate.