Improvements in the Performance of Impressed Current Cathodic Protection System with Variable Resistor at Various Environmental Conditions

摘要

This experiment represents the effect of impressed current cathodic protection with a variable resistor on concrete specimens. The effect of cathodic protection (CP) system on concrete structures can be changed at different condition. Especially, in marine concrete structures, it is difficult in applying impressed current CP by means of one rectifier in both high resistivity area (dry area) and low resistivity one (wet area). Thus, in this study, the variable resistor was utilized to fulfill similar CP effect on both high resistivity zone and low resistivity one in order to manage the problem. Specimens were concrete slab type with a base of 400mm × 400mm and a height of 70mm. Test factors were CP potential, CP current, and 4-hour depolarization potential. Test results showed that the variable resistor could have positive influences on an improvement in CP effects. In addition, environmental conditions had to be considered to reach enough CP potential and current in this system.