Square Steel Tube Impressed Current Corrosion Rate in Term of Linear Polarization Resistance (LPR) Method

Most of the civil engineering laboratory experiment induces the rate of corrosion process based on current value Am/cm² to represent the effect of corrosion, however this method has lack of quantifying the actual mass loss rate of steel in the natural environment. This paper presents the Linear Polarization Resistant (LPR) experimental test technique as supplementary method for supporting the impressed current method validation and result for square tubes with 3 mm thickness. The most important parameter of the current impressed method is the length of time required to run the test, size of the sample, and amount of current applied to achieve laboratory corrosion rate close to the natural rate. On the other hand, the linear polarization resistance (LPR) needed only 24 h to complete, and the result in this paper found correlation between the impressed current corrosion, to the LPR system in term of mass loss. Based on result of the tests, the mass loss of the impressed current can be validated by LPR mass loss yearly, which reveal the equivalent number of years needed to have natural corrosion as the same sample used in laboratory with accelerated impressed current method.