A new ground resistance-reducing material based on water-absorbent polymer

Abstract

The increase in communications facilities is accompanied by a rapid increase in the number of groundings required. However, it is difficult to achieve the required ground resistance values in areas of high grounding resistance such as volcanic ash, sandy or rocky soils, so that there is a strong need for the use of ground resistance reducing materials. This article proposes a method of reducing ground resistance using water-absorbent polymers. The use of water-absorbent polymer materials is expected to provide approximately twice the resistance reducing effect as currently used materials. When selecting such materials for placement in the soil, it is necessary to consider susceptibility to decomposition by microorganisms as well as temperature characteristics. One type of water-absorbent polymer, anhydrous maleic acid polymers, is found to satisfy both requirements. In addition, the use of such polymers as ground resistance reducing materials requires approximately 1/160 the quantity of currently used bentonite mixtures and causes approximately 1/10 to corrosion of the copper used in grounding electrodes, demonstrating that water-absorbent polymers are a highly useful method of reducing grounding resistance.