Flexural behavior of corroded HPS beams

Experimental research is conducted to investigate the flexural behavior of corroded High Performance Steel (HPS) beams. Four beams with various corrosion damage are designed and subjected to electrochemical accelerated corrosion process. 3D scanning technology is employed to analyze the geometric features affected by the corrosion damage. Flexural tests are carried out, and the impact of corrosion on the flexural response is discussed. Considering the randomness of corrosion pits in each area, predictive models are proposed for the flexural strength of corroded beams with an idealized elastic-plastic and linear-hardening constitutive relationship model. An analysis comparing the proposed models with Chinese and American codes is made. Results show that increasing the corrosion damage leads to a decrease of discreteness in the residual sectional area and causes a transformation in the compressed flange from noncompact to slender. A corrosion loss less than 10% leads to slight deterioration of both strength and stiffness degradation, while further corrosion damage results in a significant decrease. The depth and length of the buckling wavelength for corroded beams decreases gradually as the corrosion damage become more serious. The analytical models IEM and LHM or the GB50017-2017 may be suitable for predicting the lower and upper limit values of the ultimate flexural moment, respectively, and results predicted by AISC are conservative.