Interface Shear Behavior of precast prestressed concrete beams with slender webs in beam and slab bridge construction

In Ireland and the United Kingdom precast prestressed concrete bridge beams are commonly used in small to medium sized highway and railway bridges, i.e. 20m-50m spans. Over the past ten years the majority of these bridges have... [ view full abstract ]

In Ireland and the United Kingdom precast prestressed concrete bridge beams are commonly used in small to medium sized highway and railway bridges, i.e. 20m-50m spans. Over the past ten years the majority of these bridges have been built using W-beams, a U shaped precast prestressed concrete bridge beam. When combined with a cast insitu deck slab they form a composite section that must be able to resist the horizontal shearing forces developed at the interface between the two elements. Interface shear requirements are generally more onerous than flexural shear when determining reinforcement ratios and this has become quite a contentious issue for bridge engineers in recent years with differing clauses in the design codes. This paper presents work which will form part of a PhD research project examining the performance of several full scale W1 beams statically and dynamically loaded using a four point loading test with varying loading and reinforcement ratios crossing the interface. The study will compare full scale beam testing to finite element analysis using midasFEA, a computer software package. The aim of the research is to propose a minimum interface shear reinforcement equation for incorporation into Eurocode 2 Part 1-1 [1]. It is recognised that a minimum percentage of reinforcement is required across the interface to prevent interfacial slip and brittle failure at loss of adhesion. Eurocode 2 Part 1-1 [1] does not presently include a minimum requirement.