Temperature related pull-out performance of chemical anchor bolts in fibre concrete

Anchor bolts are often fixed into a concrete soffit of structures and they are used in ambient and cold store locations. The chemical anchor bolt relies purely on the tensile strength of the concrete to carry the imposed load, assuming the bond strength of the resin is greater than the tensile strength of the concrete.\ud \ud The properties of concrete are changed by the addition of both steel and polypropylene fibres. This paper investigates the relative performance of each fibre type with regard to initial and final post crack failure. Anchor bolt pull-out testing was used to determine the maximum load a fixing can hold as well as the residual post crack toughness of a bolt embedded in a concrete block. The concrete used was a C40 design mix and resin anchor bolts were selected for this test for their stress-free conditions prior to loading.\ud \ud The results showed that the addition of both types of fibres when used in concrete improved the maximum load and toughness of the samples, compared to plain concrete. There was not a significant difference between the results obtained for steel and polypropylene fibres. The effects of a reduction in core temperature of the samples was examined. The results show that the strength of concrete is significantly improved when tested at −20 °C, compared to ambient temperature.