Challenges in the Evaluation of Existing Concrete Structures: Margaret Avenue Bridge

Abstract

<p>The De la Concorde Overpass in Laval, Quebec, Canada failed in 2006 and cost the lives of five people. The failure initiated in the half-joint of the thick cantilever slab that supported the drop-in span. Following this failure, a number of owners across Canada evaluated non-redundant half-joint connections of concrete bridges, including the Margaret Avenue Bridge in Kitchener, Ontario, Canada. This paper describes the evaluation of the half-joint detail of the structure including review of existing information and a discussion of uncertainties that led to the closure and demolition of the structure. The paper critically compares observations during the demolition of the structure with the assumptions made during the evaluation. The findings during demolition confirmed the majority of the assumptions and validated the decision to demolish the structure.</p>