Round robin test to compare flexural strength test methods for steel fiber-reinforced sprayed concretes

Abstract

According to the current European standard EN 14487-1 (residual) flexural strengths of steel fiber-reinforced sprayed concrete are determined by performing a four-point bending test on beams according to EN 14488-3. Controversial to this test method, a three-point bending test on notched square panels is recommended by EFNARC. According to EFNARC, one substantial advantage of this test method is the minor scattering of the test results. Against this background, a round robin test was performed at European level. The aim was to investigate the comparability and correlation on the one hand, on the other hand to assess the precision of both test methods. The results shall provide initial pointers for the classification of the residual strengths for steel fiber-reinforced sprayed concrete with two different test methods. The results showed that the scattering of the residual strengths is marginally smaller with the test method on panels in comparison to the test method on beams. As a result, a slightly higher precision was achieved. Therefore, the EFNARC test shall be included as an alternative test procedure in EN 14487-1 in future.