Prediction of Long-Term Prestress Loss in Prestressed Concrete Beam with Corrugated Steel Web

Prestressing steel experiences stress loss by interacting with creep and shrinkage deformation of concrete in addition to its intrinsic relaxation over time. Inaccurate estimation of long-term loss can cause serviceability problems such as excessive deflection, for example, in the prestressed concrete (PC) bridge with corrugated steel webs (CSWs). This study presents a method for the long-term prediction of prestressing loss in a typical PC beam with the CSW. For this purpose, the age-adjusted elasticity modulus (AAEM) method is used, and the compliance functions are calculated using the B4 model. For verification, an experimental PC beam with CSW was tested under sustained dead load and prestressing. The experimental long-term mid-span deflection data were compared with the proposed method as well as finite-element results, which showed a good agreement with each other. The results suggest that the proposed method can be used confidently. Furthermore, a parametric study was performed to evaluate the effect of parameters such as geometric of CSW, loading age, effective thickness, and relative humidity on the long-term behavior of this type. These parameters were used in the long-term numerical analysis using the proposed method, and their sensitivity to the results was investigated. The results show that the decrease in relative humidity and loading age and geometric values of the width to depth ratio of CSW less than one can increase deflection and prestressing loss.