Improved flexural strength and morphology of gypsum by wollastonite

Abstract

The role of β-wollastonite on the flexural strength of gypsum obtained from the hydration of alpha-hemihydrate was investigated in this work. Starting with a synthesized Xonotlite obtained from the industry, dehydration was carried out at 880°C giving rise to the β-wollastonite which was identified by X-ray diffraction. The pure gypsum samples were prepared and compared with 3% and 5% replacements of the wollastonite. Increased flexural strengths were observed for 2, 7 and 28 days of storage in room temperature, normal water, and cold water. It was remarkable that the strength in water storage increased. The crystal morphology of the obtained gypsum was also improved in the presence of β-wollastonite.