Interlaboratory evaluation of experimental setups for textile reinforcements

Abstract Reliable test methods that provide reproducible results are essential for the mechanical characterisation and standardisation of textile reinforced concrete (TRC). This paper presents the results of an interlaboratory study comprising uniaxial tensile tests and bond tests on TRC with various textile configurations. All laboratories conducted the experiments in accordance with predefined test protocols. The results were statistically evaluated with respect to scatter, repeatability, reproducibility and intraclass correlation coefficients (ICC). The uniaxial tensile test exhibited low interlaboratory scatter and a uniform mechanical response across all participants. Both the qualitative behaviour and the derived characteristic values showed close agreement, indicating that the applied procedure enables reproducible characterisation under controlled conditions. In contrast, the bond test revealed a higher level of scatter. This increased variability is attributed primarily to the greater sensitivity of the test arrangement and the inherent complexity of the bond interaction, rather than to systematic laboratory-dependent influences. Despite the larger numerical variability, the overall response characteristics were consistent across laboratories, demonstrating that the governing bond mechanisms were captured in a comparable manner. The results underline the need to combine quantitative evaluation with qualitative assessment when interpreting bond test data, providing a basis for further refinement and potential standardisation of the applied test methods.