Physico-chemical performance of a metakaolin geopolymer added with TiO2 particles

Abstract

In the present study is evaluated the performance of a geopolymer produced using metakaolin as precursor with additions of titanium dioxide (TiO2) particles up to 10%. A mixture of potassium hydroxide and potassium silicate was used as alkali activator. The properties studied in both fresh and hardened state were setting time and compressive strength. Complementarily, microstructural characteristics were evaluated in the material using techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). Based on the obtained results it was possible to conclude that the addition of TiO2 in the evaluated percentages does not affect the compressive strength of the geopolymer and, on the contrary, it is possible to reach increments of this property in the order of 10.3%; however, the setting times of the material were negatively affected after the addition of TiO2 particles, being reduced by up to 31.1%. The addition of TiO2 particles in the material does not affect the formation of the main hydration product of the geopolymer (K-A-S-H gel).