Electrical conductivity of setting cement paste with different mineral admixtures

Characterization of Cement Paste in Fresh State Using Electrical Resistivity Technique

“…Bekir at al. [13] found that for all the paste mixtures including paste without SCMs and pastes with SCMs such as fly ash, silica fume and blast furnace slag, increasing the water/binder (OPC plus SCMs) increases the electrical conductivity (decreases the electrical resistivity). Furthermore, rate of decrease in electrical conductivity is more for lower water/binder ratios than that of higher w/c ratios.…”

“…Bekir at al. [13] conducted the Vicat needle test to determine the initial and final setting time of pastes with and without SCMs such as fly ash, silica fume and slag. They reported that in general, the final setting time of pastes containing SCMs increased compared to that containing only OPC.…”

“…Furthermore, Salem in another study [9] observed that increasing silica fume from 10 to 50 percent replacement in OPC pastes decreased the conductivity at the early stage (see Bekir et al [13] studied the electrical conductivity of cement pastes at early age (1 day).…”

“…K + and Na + ) [9]. Bekir et al [13] reported that at a certain w/c ratio, conductivity of the paste at early age decreases if it contains SCMs such as fly ash, silica fume and slag. They suggested that slower pozzolanic reaction with water and hence release of less ion as well as decreasing volumetric fraction of the liquid phase because of increased volume of solid phase due to less specific gravity of SCMs 53 compared to OPC, contributed to this decrease in conductivity.…”

“…Electrical resistivity measurements have been known to characterize the concrete behaviour as a non-destructive test since 1950s [3]. In recent years, the number of investigations on the subject has increased dramatically [4][5][6][7][8][9][10][11][12][13][14][15] For example, Xiao et al [2] reported that the compressive strength of hardened paste at early age can be estimated accurately from associated electrical resistivity measurements, as shown in Fig. 1.1.…”