Performance of eccentrically loaded slender circular CFSTs subjected to localized pitting corrosion

This paper focuses on the performance of eccentrically loaded slender circular concrete-filled steel tubes (CFSTs) subjected to localized pitting corrosion. It was demonstrated through tests on seven CFST specimens that an increase in the degree of volume loss and corrosion width can degrade the behavior of the beam-columns. The influence of varied diameter-to-depth ratios of pits can be disregarded. Following observations from tests, numerical models were established, validated, and then extended to account for the random nature of corrosion pits. A parametric analysis illustrated that the degree, dimension, and location of localized pitting corrosion had a considerable impact on the ultimate strength and the shape of the lateral deflection profile at the peak load. It was found that in the case where slight corrosion was located near the column end, effects from corrosion on the behavior of beam-column could be ignored. By modifying the methods in current codes, simplified calculation methods were proposed to calculate the ultimate strength of members featuring corrosion at midspan. Considering the random corrosion locations, a controlling-section based method was also developed for estimating the ultimate strength. The method could determine whether the corrosion should be considered, and reasonable accuracy was achieved.