Steady-State and Transient Elevated Temperature Testing of Single Lap Adhered Steel Connections

Abstract Adhesives have demonstrated promise for use in the steel industry as they provide strength and stiffness throughout the entire connection area without introduction of residual stresses. Moreover, the controlled environment of prefabrication plants is ideal for adhesive connection assembly. Despite success in other heavy structural settings including glue- and cross-laminated timber construction and concrete anchoring systems, adhesives remain underutilized and relatively unexplored in steel construction. For broad acceptance of adhered connections, a complete understanding of their behavior in service and extreme conditions is required. The performance of adhered steel connections under elevated temperatures is evaluated in this first of its kind study through the testing of 46 single lap splices adhered with two adhesives under steady-state (SS) and transient state protocols at the Multi-Hazard Resilient Structures Lab at Johns Hopkins University. Both adhesives demonstrated sensitivity to elevated temperatures, though the acrylic adhesive tested in this study showed greater resistance to temperature than the epoxy. From this novel set of experimental data, unique strength retention curves were developed for both types of adhesive connections. These can be used to predict performance at elevated temperatures and design resilient adhesive steel connections. In aggregate, the results demonstrate that the tested structural adhesives can be used in steel connections provided they are adequately insulated with fire protection.