Comparison of Thaumasite Sulfate Attack Formation Speed Under Different Erosion Conditions

Abstract:

A comparative study was made of the thaumasite formation speed of the specimen under the condition of electric pulse and the condition of common immersion. The erosion products generated by the two acceleration methods were analyzed by scanning electron microscope (SEM/EDS), X ray diffraction (XRD), and Fourier transform infrared spectroscope (FTIR) and appearance changes of the specimen were observed after different testing time. The results show that the electric pulse obviously accelerates the thaumasite formation of cementitious materials. There is a preparation period of the thaumasite sulfate attack(TSA) reaction in the specimen, when electric pulse act on it from the 90th day to the 120th day; abundant thaumasite is found in the erosion products after the 120thd. However, in the group of common immersion, there are some raw materials needed by the thaumasite formation in the specimen after the 1st year, and only a very small amount of thaumasite is found.