Experimental study on concrete edge failure of single headed stud anchors after fire exposure

In the present study different single headed stud anchors are exposed to various durations of fire and loaded in shear perpendicular to and towards the free concrete edge up to failure after cooling. The effects of concrete edge distance, nominal diameter, embedment depth and concrete compressive strength on the load-bearing behaviour of the anchors at various durations of fire are experimentally investigated. The standard fire curves ISO-834 with the corresponding durations of 15 min and 60 min are employed to study the effect of fire on the residual capacities of the anchors. Even more than expected, the results demonstrate that the anchor behaviour is significantly influenced by the fire exposure. Under ambient conditions, the influence of the edge distance on anchor resistance is very strong while the influence of the anchor diameter and the embedment depth is relatively weak. However, after fire exposure the influence of the edge distance reduces and the influence of the diameter and the embedment depth on the shear resistance increases. The influence of fire exposure is significant on the concrete edge capacity of the anchors. After only 15 min of fire duration, the reduction of more than 50% of the reference value is reported.