Investigation and Review of Structural Adhesives for Steel Bridge Repair and "Steel Grouting"

Traditional methods of repairing steel bridges often involve welding or mechanical fastening, processes that can be time-consuming, expensive, and disruptive to traffic flow. In response to these challenges, the utilization of structural adhesives has emerged as a promising alternative for steel bridge repair. Structural adhesives can exhibit fluid or injectable properties, which are ideal for filling small gaps or cracks in steel bridge applications with minimal surface preparation required during application. Alternatively, they may demonstrate viscous or putty-like behavior, suitable for packing into more significant gaps. Structural adhesives offer advantages such as enhanced durability, corrosion resistance, and ease of application by providing high-strength bonding solutions. This approach presents a promising avenue for effectively addressing gap-related issues in steel bridges. However, uncertainties persist regarding the compressibility of adhesives at different thicknesses under sustained compressive and environmental loads, as well as the slip coefficient of adhesives applied to fill gaps on faying surfaces. Furthermore, despite the wide range of structural adhesives used across various industries, there is limited information on the selection of adhesives for steel bridge repair applications.

This study comprehensively explores structural adhesives selected for gap filling in steel bridges, “steel grouting,” to prevent crevice corrosion and enhance loading conditions. The study incorporates bulk materials testing of selected structural adhesives and structural testing of steel connections. It evaluates various material properties, including compressive strength and creep behavior under sustained compressive conditions and temperatures in environmental cure conditions. Compressive creep tests are conducted to quantify the compressibility of structural adhesives while considering environmental factors. Slip tests are performed to determine the slip coefficient of adhesives in slip-critical bolted connections, and tensile creep tests are carried out to assess the slip performance of adhesives under sustained tensile and environmental loading with different steel surfaces. Additionally, the project includes a literature review focusing on structural adhesive selection and an analysis of previous testing methodologies and industrial usage. The findings of this study contribute valuable insights into structural adhesive behavior and performance through meticulous experimentation, literature review, and analysis, informing future selection and application techniques in steel bridge maintenance and repair.