Experimental Study on the Flexural Performance of Composite Beams with Corrugated Steel Webs under the Coupled Effect of Chloride Ion Erosion and Sustained Load

The steel corrosion of composite beams with corrugated steel webs (CBCSWs) is prone to occur in a chloride environment, and the load can change the rate of steel corrosion, thereby affecting the degradation of the mechanical properties of CBCSWs. In this paper, the flexural behavior of CBCSWs under the coupled effect of chloride ion erosion and sustained load was studied through an accelerated corrosion test and bending failure test. The results showed that, during the accelerated corrosion test, the deflection at the mid-span of the corroded CBCSWs increased more and faster than that of the uncorroded CBCSWs, and the stress of the externally prestressed tendons of the CBCSWs did not change significantly. During the loading failure process, the relative slip between the web and the concrete plates of the corroded CBCSWs had not been fully developed. The ultimate load and ultimate deflection of the corroded CBCSWs were decreased by 41.1% and 17.9%, respectively, compared to those of the CBCSWs before corrosion. The quasi-plane section assumption was still approximately applicable to the corroded CBCSWs. Compared with the uncorroded CBCSWs, the shear lag effect of the top plate of the corroded CBCSWs was more obvious. The externally prestressed tendons of the corroded CBCSWs could not give full play to their performance during the process of loading failure.