Electrophoretic nuclear magnetic resonance measurement of electroosmotic flow and dispersion in hydrating cement paste

This research analyzes the effect of an applied electric current on the dynamic displacement behavior of hydrogen ions in a hydrating cement paste confined in a closed cell. Electroosmotic flow (EOF) and dispersion in hydrating cement pastes is measured via the nuclear magnetic resonance (NMR) pulsed gradient spin echo technique (PGSE). The dynamic PGSE NMR measurements indicate changes in pore structure after the application of the electric field. Micro CT scan imaging experiments confirmed that gaseous and fluid pore pressure is sufficient to cause particle rearrangement, consolidation, and void formation at relatively low voltages when the electroosmotic pressure approaches its maximum in a medium closed to external flow. Such phenomena may also result where blocked pores present restrictions in a medium otherwise open to flow.