Spontaneous electrical effects in masonry affected by capillary water rise: The role of salts

The investigation of the electrical effects accompanying capillary water rise from ground in old masonries is of great practical interest, as such effects might be exploited for both measurement purposes (determination of moisture and soluble salts) and for dehumidification purposes (techniques based on electrokinetic principles). present paper, the spontaneous dc voltages arising in a real-scale masonry model subject to a steady-state capillary flux of saline solutions (0.05 M sodium chloride and 0.05 M sodium sulphate in water) were measured. The resulting voltage depends on the amount and distribution of salts, rather than on moisture content in the masonry.