229. LONG-TERM INTEGRITY OF EPOXY-BONDED REBAR COUPLERS
Department: Structural Engineering
Name: Griffin R Brungraber
Grad Year: 2009
Steel Reinforcing Bar (Rebar) couplers mechanically link pairs of steel reinforcing bars, end-to-end; they are used regularly in reinforced concrete construction. Epoxy-bonded couplers are one available type, but introduce new long-term integrity considerations to reinforced concrete design. The epoxy material used in these couplers is a two-part, field-mixed, ambient-cure system, originally designed for adhesive anchorage to concrete. The mechanical properties of these types of epoxies could potentially deteriorate over time. The performance of the epoxy materials and couplers are being measured over a sixteen-month period of environmental exposure and the material response is being correlated to the system response. A Finite Element Analysis (FEA) will correlate the changes in epoxy mechanical material properties with changes in system behavior. During a preliminary de-selection testing program in 2006, two epoxy systems were selected for further research. An environmental testing program has been started that will run from summer of 2007 to the end of 2008. Moisture uptake, material tension, material compression, dynamic mechanical thermal analysis (DMTA), and coupler system tension are included in this test program. The results of this test will be used to develop an Epoxy-Bonded Rebar Coupler test protocol, program or specification for The California Department of Transportation (CALTRANS).