Nondestructive monitoring the deterioration process of cement paste exposed to sodium sulfate solution by X-ray computed tomography

X-ray computed tomography (X-ray CT) method is proposed to in situ monitoring the damage process of cement paste containing different water-to-cement ratio (0.55, 0.40) exposed to sodium sulfate solution. In addition, the corrosion products were analyzed by X-ray diffraction (XRD). The results show that X-ray CT can track the time-dependent development of cement paste exposed to sodium sulfate solution. Furthermore, the information of cracks spatial distribution, gray values, corrosion depth and pore volume distribution can be clearly obtained by this method. Additionally, XRD results show that the main corrosion products of the cement paste with high water-to-cement ratio are ettringite and gypsum in the later stage.