Methods to Develop Composite Action in Non-Composite Bridge Floor Systems: Part I

Over six percent of the bridges in Texas are considered structurally deficient, with about 3500 bridges posted for load, meaning that they do not meet today’s design load ratings. More than one out of every eight bridges is proposed to be replaced, at a cost of $15 billion, because of insufficient capacity or roadway geometry. Economic methods of rehabilitating the structurally inadequate bridges are highly desirable. Creating composite action in currently non-composite bridge floor systems may be such a method, given that two out of every five bridges are composed of steel girders topped with concrete slabs.

This thesis, combined with that of Hungerford (2004), investigates the viability of post-installing shear connectors. Of the fifteen connectors investigated, the static load-slip characteristics of twelve post-installed shear connectors was assessed, resulting in the recommendation of seven connectors for further testing. A static single-connector direct-shear test was performed on each tested connector, in lieu of the more traditional push-out test. Data on the coefficient of friction between the steel beam and concrete slab was also collected, as some of the connectors rely on friction at the steel-concrete interface as the primary shear force transfer mechanism.