STABILITY AGAINST TEMPERATURE AND ENVIRONMENT FOR GROUND-RESISTANCE REDUCING MATERIAL USING WATER-ABSORBENT POLYMER

As the number of communication facilities increases, the number of groundings installed in such stations also increases. It is difficult to achieve the specified ground-resistance value in such high ground-resistance regions as volcanic ashes, sands, and rocks. In this paper, as a ground-resistance reducing material, a water-absorbent material solidified by plastic hardener is treated. Its stability in an air and water environment is described. As a water-absorbing material, anhydrous maleic acid polymers are selected. It is found that this material maintains the characteristics for about 10 years if the performance degradation of 20 percent is allowed and about 20 years if 50 percent is allowed. For the reducing material made of an absorbing material solidified by epoxy, it is found from the environmental degradation characteristics by changing the temperature in air that the dry condition can be allowed for about one year during which the ground resistance can maintain its initial value if rain falls and is sufficiently stable. Further, from the environmental degradation characteristics in water, it is found that the ground resistance maintains the initial value and the compression strength is not degraded unless the temperature is more than 70 degrees C. Hence, the stability is sufficient even in water.