Investigation of ASR in the Old Alexandra Bridge, British Columbia

Serving as a critical link on the TransCanada Highway since the 1920s, this historic bridge provided an important connection over the Fraser Canyon in southwestern British Columbia for vehicle traffic until being taken out of service in the 1960s. Today it is regarded as a heritage structure and has, until recently, been a tourist attraction for hikers and other recreational users. Its concrete elements have, however, been affected by deterioration to variable extents. In this paper, we present some of the results regarding the effects of Alkali-Aggregate Reaction (AAR) and the role that it has played in the condition of the concrete. The methods used included site reconnaissance and inspection, core sampling, saw cut sampling, petrographic examination, compressive strength tests, and Damage Rating Index evaluations. These methods and data are presented and form the basis for an analysis of not only the new information gathered but also the limitations inherent to these approaches, as pertaining to this structure.