Effect of C3A on Performance of Thaumasite Form of Sulfate Attack of Silica Minerals

Abstract

The effect of tricalcium aluminate (C3A) on the erosion degree and products of silica minerals under the thaumasite form of sulfate attack condition was studied using X-ray diffraction (XRD), a scanning electron microscope (SEM), and an energy dispersive spectrometer (EDS). The results show that C3A accelerated the formation rate of thaumasite, and the improvement degree depended upon C3A dosage. Crystal structures presented that the erosion products were thaumasite form solid solution after attack, and the value a decreased with increasing of C3A content, but value c had the opposite result. The morphology of the solid solution indicated that the crystal size became smaller as the C3A dosage increased.