Abstract:The effect of mineral admixtures on sulfate attack for mortars subjected to electrical pulse was investigated by the appearance observation and strength measurement on the mortars with and without mineral admixtures under electrical pulse and immersion. The microstructures of the damaged specimens were analyzed by using scanning electron microscopy and energy dispersive spectrometer. The results showed that electrical pulse accelerated the penetration of the external sulfate ions into the mortars, and the sulfates then reacted with the cement hydration products to form massive ettringites. As a consequence, the specimens displayed significant cracking and spalling as well as strength reduction within a short period. Mineral admixtures improve the sulfate resistance performance of the mortars, and the improvement is increased with the increase of the amount of the admixtures. However, the mortars blended with mineral admixtures were still subjected to the dramatic sulfate corrosion under electrical pulse. The above findings indicate electrical pulse the accelerated sulfate attack, and also provide a new idea in rapidly evaluating the sulfate resistance of cement-based materials.