Factors Influencing the Thermal Behavior of Adhesive Anchor in Steel-to-Concrete Connection at Elevated Temperature

As an effective tool for post-installed anchorage adhesive anchor is widely used in steel-to-concrete connection for structural retrofit, however the bond strength of adhesive would have significant reduction at elevated temperature. Therefore this paper proposed a numerical analysis of 3D FE model to investigate the performance of steel-to-concrete connection exposed to fire. Variables that affect the thermal response of adhesive anchor including fire resisting coating´s thickness, edge distance, fire protection area and embedment depth of anchor have been studied. The results show that thicker fire resisting coating can provide better protection for inner anchor and control the anchor temperature in a lower level, the maximum temperature of anchor in the case of edge distance 40mm would reach above 600°C after a fire exposure of 90 minutes. Compared with the total coating protection on concrete surface, partial protection measurement tends to lead to disuniform temperature distribution on concrete surface in the early stage of heating. The increase of embedment depth has slight effect on temperature gradient of anchor at elevated temperature.