Synchrotron Radiation Diffraction Study of the Microstructure Changes in Cement Paste due to Accelerated Leaching by Application of Electrical Fields

Abstract

An external dc voltage was applied to cured cement pastes to simulate their natural degradation over time; i.e. migration of ions and dissolution of solid phases. The presence of crystalline phases before and after applying a voltage was quantified by powder diffraction using synchrotron X-ray radiation. The results were refined by the Rietveld method. The specimens were also analysed by mercury intrusion porosimetry. Results indicated that a portion of the crystalline phases dissolved and later precipitated as amorphous phases in smaller pores. This accelerated treatment led to the formation of a larger proportion of amorphous phases in the specimens studied.