Thermal and fatigue testing of fiber reinforced polymer tie connectors used in concrete sandwich walls

摘要

The purpose of this research program was to determine the strength, strain, fatigue, temperature, and other corresponding behavioral characteristics of concrete sandwich wall panels containing the new Delta TieRTM fiber reinforced polymer (FRP) tie connector produced by Dayton/Richmond, a brand of Dayton Superior. The scope of this program included a matrix of three full-scale 40\u27-0\u27\u27 wall panels subjected to a 100°F temperature differential, and a matrix of six elemental specimens, three with the ties oriented in the strong direction (parallel tie orientation) and three with the ties oriented in the weak direction (perpendicular tie orientation), subjected to cyclic load tests for determination of fatigue characteristics and in-plane shear capacities of the Delta Tie. The scope of this research included deformation measurements, strain measurements, temperature recordings, fatigue strength determinations, and theoretical analysis for comparison to experimental results.;The results of this research indicated that when subjected to a 100°F temperature differential, the full-scale wall panels did not experience bowing displacements of large enough magnitude to cause in-plane shear displacements in excess of the maximum capacity of the Delta Tie. Also, observation of the results indicated that wall panels constructed with closer tie spacing experienced a larger value of composite behavior. Additionally, the results of this research indicated that the maximum in-plane capacities of the Delta Tie were approximately 3300 lbs or 0.043 inches of displacement for ties oriented in the strong direction and approximately 3000 lbs or 0.027 inches of displacement for ties oriented in the weak direction. Based on the cyclic loading used in the scope of this research, the fatigue characteristics of the Delta Tie were not significant; however, when orientated in the strong direction, the Delta Tie maintained some magnitude of mechanical anchorage between concrete wythes, which was not quantified within the scope of this research.;Given the scope and results of this research, the Delta Ties performed adequately under the 100°F temperature differential and the recommended orientation for Delta Ties used in composite sandwich wall construction is the parallel tie orientation