Identifying factors influencing the corrosion rate of steel using nonparametric statistics

Statistical techniques have made it possible to describe the behavior of certain phenomena. Nonetheless, given the difficulty in obtaining adequate data, it is common not to have random and homogeneous samples in order to conduct parametric statistical tests (which follow a known distribution). The present study reports results from the use of a non-parametric statistical test (which does not follow a known distribution) known as the Mood test of median differences which was conducted to analyze the corrosion rate of concrete beams exposed to different environmental conditions. The main objective was to statistically determine which factors accelerated the corrosion rate of the beams under study. Results showed that the tested factors (three different concrete covers: 15, 20 and 30 mm, and two water/cement ratios: 0.45 and 0.65), had statistically significant effects on the corrosion rate. Greater corrosion rates were observed for beams with covers of 15 and 20 mm, and with a water/cement ratio of 0.65. Nonetheless, we found that the corrosion rate was not statistically different between sides of the beam facing prevailing winds, and those that were sheltered from the

Statistical Analysis of Factors Influencing Corrosion in Concrete Structures

The use of mathematical and statistical models has allowed the description of the behavior of many natural phenomena. However, their application in civil engineering particularly, for the analysis of the corrosion behavior, has been overlooked in recent studies. In the present work, a factorial analysis with subdivided parcels design were conducted to evaluate the corrosion rate behavior of arrangements of protected and not protected steel bars found in reinforced concrete specimens subject to two different aggressive media. The results showed that, in comparison to sulphate ions, the effect of chloride ions on the corrosion rate was not statistically significant. In the same way, protected and not protected segments on the steel bars (i.e., steel bar condition) did not have a significant effect on the corrosion rate. The only factor found to significantly affect the corrosion rate was the variability of the beam fabrication process (i.e., beam factor)