A test procedure for evaluating the impact behaviour of fibre reinforced concrete

Many structures are subjected to impact and diverse alternatives to measure the concrete performance under these loads have been developed. In this paper a test procedure for evaluating the contribution of different types and contents of fibres on the impact response of Fibre Reinforced Concrete (FRC) is presented. A study on the variability of results, in order to define the minimum number of tests, and results of preliminary experiences for evaluating the losses of energy during the tests, are included. The methodology is based on drop-weight repeated impacts in bending. The equipment and the procedure are descripted, as well as the impact parameters proposed for measuring fibre concrete performance both at cracking and in cracked state. It was found an acceptable coefficient of variation (< 20%) of total cumulated energy ( E T ). Considering this parameter 6 tests are enough for obtaining an Error lower than 15% with a Confidence Level of 90% to measure the impact first-crack resistance and the behaviour in cracked state of FRC. The test is both easy and of quick execution and is capable to distinguish the effect of significant factors, such as the type and content of fibres.