Behaviour of Mild Steel in Egyptian Soil with special reference to Particle Size: II. Effect of resistivity, water content and temperature differentials

Abstract

The resistivity of the coarse sand (particle size range: 2·4–0·84 mm) was found to be higher than that of the fine sand (particles of size < 0·385 mm) brought from the Giza Pyramids area in Egypt. Differential water content conditions lead to an increase in the galvanic current for mild steel couples immersed in this sand. The potential of the steel placed in the just-wet region shifts to more positive values due to the increased oxygen content in these regions. Heating of one of the electrodes of the couple increases the galvanic current in water saturated cells and decreases it in differential water content cells where one of the electrod]es is left in a just-wet region and the other is in water saturated soil. Consecutive heating and cooling of one of the two electrodes increases the galvanic current of the couple and this increase is higher infine sand than in the coarse one.