Fluorgypsum binders with fly ash, cement and activators, strength and microstructures

In this article, chemical compositions of fluorgypsum were qualitative and quantitative analyzed by using X-ray. Cementitious composites based on 70% fluorgypsum, 15%fly ash, 10%cement, 2%glass fiber, 2%sawdust, three activators best mixed content KAl (SO₄)₂ 0.5%, K₂SO₄ 0.3%and Na₂SO₄ 0.2%, were wet cured for up to 180 days at 30°C. The products developed and maintained strength up to 26MPa. Characterization by scanning electron microscopy and X-ray diffraction indicated that gypsum formed intensively in the 24 hours, and with the increase of curing time, the strength increase, the activators play an important role in this process. We also obtained the hydration of fluorgypsum systems are C-S-H, gypsum and ettringite.