Evaluation of mortar setting time by using electrical resistivity measurements

Alkali-Activated Slag Paste with Different Mixing Water: A Comparison Study of Early-Age Paste Using Electrical Resistivity

“…Wenner's four-electrode method was used to monitor the electrical resistivity of alkali-activated GGBFS (AAS) paste, for 24 h, mixed with deionized water or seawater. This method was verified by previous experiments that measured the electrical characteristics of various types of cement-based materials without an electrode contact error [10]. The schematic experimental setup, four-electrode setup for electrical resistivity measurement, and four-electrode method are illustrated in Figure 2.…”

“…The four electrodes used in this setup is divided into two parts: two electrodes on the inside for measuring current and two electrodes on the outside for measuring potential. The spacing of the electrodes was optimized at 20 mm [10]. Copper electrodes with a diameter of 1.78 mm were inserted at 20 mm from the surface to the middle of the sample.…”

“…To evaluate the setting time and hardening of cement-based materials, various nondestructive techniques have been proposed using ultrasound inspections and electrical estimation, including the Vicat needle test [10][11][12]. Among them, electrical estimation is one of the simpler and promising methods, owing to its superior sensitivity in suspension and quick measurements with a cost-effective testing setup.…”

“…This characteristic has been used to investigate the effect of admixtures in cement-based mixtures based on the measurements of electrical resistivity [13,14], and a saturating condition in cement paste and mortar was considered to measure an electrical resistivity [15,16]. It has been applied to hydration monitoring [10,[17][18][19][20]. To prevent the erroneous effect of electrode contact resistance in cement-based materials, the four-electrode method was used and electrical resistivity was monitored [10].…”

“…It has been applied to hydration monitoring [10,[17][18][19][20]. To prevent the erroneous effect of electrode contact resistance in cement-based materials, the four-electrode method was used and electrical resistivity was monitored [10]. Electrical estimation can nondestructively evaluate the generating hydration products and monitor a degree of hydration in early-age suspension.…”