Adhesive Anchors in Concrete under Sustained Loading Conditions
Adhesive anchor systems are commercial adhesives — often, but not exclusively, epoxy adhesives — used to anchor threaded metal rod and rebar into concrete. In many applications of these systems, the adhesive anchor is under a sustained tensile load, mandating the use of adhesives with strength and creep behavior appropriate to the load and expected service life, the anchor installation details, and the environmental conditions at the anchor. To help advance knowledge in this area, TRB’s National Cooperative Highway Research Program (NCHRP)
Report 639: Adhesive Anchors in Concrete under Sustained Loading Conditions explores a test method designed to help determine an adhesive anchor’s ability to resist sustained tensile loads. The test method builds on current methods from the American Association of State Highway and Transportation Officials (AASHTO), American Society for Testing and Materials (ASTM), state departments of transportation, and other sources and considers the creep characteristics of the adhesive throughout the expected life of the structure, site-specific ultimate strength requirements, and the effects of temperature and moisture.
Bridge Management Systems for Transportation Agency Decision Making
Designing, building, maintaining, repairing, and replacing bridges involve critical investment decisions for agencies because of the high cost of these investments, the need to sustain an appropriate level of investment throughout the considerable life of a bridge, and the important structural and functional implications of the selected investments. Decision-making regarding the funding of state and provincial bridge programs occurs at different organizational levels within departments of transportation. To help advance knowledge about the different processes, TRB’s National Cooperative Highway Research Program (NCHRP)
Synthesis 397: Bridge Management Systems for Transportation Agency Decision Making gathers information on current practices that senior managers at transportation agencies use to make network-level decisions on resource allocations for their bridge programs. In particular, the study explores how agency bridge management systems are employed in this process.