Wenner Probe Technique Application in Electrical Resistivity and Corrosion Potential Measurements of Concrete Induced Chloride threshold Mechanism
Abstract
The research evaluated Musanga cecropioides extrusion viscosity gummy paste (exudate/resin) obtained from trees as a corrosion inhibitor material to slow down the impact of corrosion on steel bars embedded in concrete and constructed in high-salinity coastal areas. The exudates/resin extracted is coated on the steel bar and embedded in the concrete slab, exposed to the corrosive medium with high salt concentration. The hardened concrete slab is completely immersed in a 5% aqueous sodium chloride (NaCl) solution, and the rapid corrosion process accelerated for 360 days with interval inspections and routine tests at 90 days, 180 days, 270 days, and 360 days for comparative evaluations for both uncoated and coated samples. The computed maximum control percentile value is -67.28% compared to the corroded and coated values 241.14% and -64.4% and the controlled potential difference value is 4.99%, corroded 60.25%, and coated 6.29%. The maximum yields of the controlled and coated samples were -105.1mV and -113.74mV, with the result obtained, this showed an indicative relationship between corrosion potential and probability as πΈcorr > β200mV as the reference range. These results of potential Ecorr results showed indication that the values of controlled and exudates/ resin coated specimens are low with the range of 90% probability that no reinforcing steel corrosion is occurring in that area at the time of measurement (10% risk of corrosion which indicates a 10% or uncertain probability of corrosion. For the non-coated sample, the maximum obtained computed value is -328.64mV, the results are within the range reference of dependence between potential and corrosion probability of the value β350mV β€ πΈcorr β€ β200mV indicating a high range of values, notifying a 10% or uncertain probability corrosion. The comparative results from the referencing range (controlled), showed that corroded samples exhibited corrosion presence resulting from the induced corrosion acceleration against coated samples that exhibited absence of corrosion. The exudates/resins exhibited inhibitory characteristics against corrosion attacks on reinforcing steel embedded in the concrete slab, exposed to corrosive media by the formation of the resistive coating. The maximum computed percentile of the controlled sample of concrete resistivity is 149.21% compared to the corroded and coated value of -59.26% and 153.52% and the maximum percentile difference of control is 5.38% compared to the corroded and coated value of 1.3 % and 8.09%. The results of the controlled and coated concrete resistivity samples obtained at an average maximum value of 15.85kΞ©cm and 16.23kΞ©cm with a data value of 10 <π <20 (low) compared to a corrosion value of 6.45kΞ©cm with specifications (π < 5, 5 < π < 10, 10 < π < 20, π > 20) and with the reference range of the relationship between concrete resistivity and corrosion probability, the significant corrosion probability (π < 5, 5 < π < 10, 10 < π < 20, π > 20) was very high, high, low to medium and low, for corrosion probability. The computed maximum percentile of the controlled yield strength is 8.96% compared to the corroded and coated values -7.83% and 9.08% and the possible difference values are 0.45% controlled, 0.49% corroded, and 0.59% coated. The maximum computed difference in values is 1.83MPa and 0.01% the controlled tensile strength is 3.478% against the corroded and coated values, respectively are -2.942% and 5.408% and the potential difference values 0.01% controlled, 0.01%% corroded and 0.01% coated. The yield strength, tensile strength, and strain ratio of the mean, percentile, and differential potential values of the control, uncoated (corroded) and coated concrete slab samples showed that coated samples had higher failure loads compared to corroded samples with reduced and decreased failure loads and low load-bearing capacity and with average values and percentiles to the reference range, while uncoated (corroded) samples recorded lower loads carrying capacity and reduced value compared to the reference range. The diameter of reinforcement after corrosion maximum computed percentile value is 0.039% as against -1.116% corroded and 1.128% coated; the difference in percentile is 0.005% corroded versus 0.008% coated. The results of the comparative of corroded samples show the reduction in values compared to the diameter of the reinforcement before and after the induction accelerated corrosion test with a percentile range for the reduction value from 0.039% to -1.116% and the average value in the range from 11.99mm to 11.94mm. The decrease/increase (diameter) in the cross-section of the minimum and maximum mean and percentile values were controlled 100%, with no decrease or increase in the description after 360 days of immersion in fresh water. The decrease in mean and percentile values indicates that the corrosion effect causes a reduction in diameter and cross-sectional area, fiber degradation, ..........