Electric polarization and depolarization in cement-based materials, studied by apparent electrical resistance measurement

Electric polarization in cement-based materials (without conductive admixture) under an applied DC electric field was found by apparent electrical resistance measurement to be faster than subsequent depolarization under a reverse field by a factor ranging from 5 to 8. The slow depolarization suggested a degree of ionic trapping. In contrast, depolarization was even faster than polarization in carbon fiber cement, due to the fast hole response. Sand addition slowed down polarization saturation, but enhanced the polarization. Silica fume addition did not slow down polarization saturation, but diminished the polarization slightly. An increase in temperature enhanced the polarization due to increase in ionic mobility.