The appearance observation,mineral composition,as well as microstructure morphology towards various cement pastes and motars with and without 30% fly ash or 50% slag dipped in 5% Na2SO4 solution at room temperature for 2 years were character-ized by X-CT,X-ray diffraction and scanning electron microscopy to investigate the effects of mineral admixtures such as slag and fly ash on the sulfate resistance performance of cement-based materials from the micro-level angle.The results show that the specimens witho...