Modified Yield-Line Theory for Prestressed Concrete Deck Slabs with Interface between Old and New Deck Slabs

Abstract

In a technique for widening prestressed concrete (PC) deck slabs proposed by some researchers in Japan, the shear transfer between the old and new deck slabs is achieved through the external prestressing force, and the rebars extending from the old to the new deck slab. To simulate this condition in the experimental test, three PC deck slabs under a concentrated load were tested by taking the initial prestressing level as the parameter. Observations suggest that the capacity of the widening PC deck slabs was difficult to predict due to the current analysis technique does not consider the presence of the interface between the old and new deck slab. Therefore, the conventional yield-line theory, as one of methods for calculating the flexural capacity, was modified in this study. The results indicated that the modified yield-line theory showed better accuracy compared to the conventional yield theory for lower initial prestressing level. However, for higher initial prestressing level, both conventional and modified yield line theory highly overestimated the experiment.