Behaviour of round steel fibre reinforced concrete panels under point loads

The objective of this investigation was to examine methods of testing round Steel Fibre Reinforced Concrete (SFRC) panels to obtain empirical estimate s of post-crack load capacity under point loads. The performance of steel f ibre reinforced concrete panels under point loads is of interest because su ch tests are commonly used to determine the suitability of a concrete mix f or use in sprayed tunnel lining construction. This investigation has focuss ed on experimental obstacles to the reliable determination of post-crack lo ad capacity. To examine possible differences in behaviour between continuous in situ tun nel linings and specimen panels representing portions of a lining, four mod es of edge support were used to restrain round specimens that varied in bot h thickness and diameter. Determinate and simple support conditions were ex amined as possible modes of panel support for routine laboratory testing. F ully clamped and quasi-continuous edge restrained panels were used as appro ximations of an in situ lining. Performance was measured in terms of peak l oad capacity and energy absorption.