Investigation on triaxial compressive mechanical properties of ultra high toughness cementitious composites with high strain capacity

Ultra high toughness cementitious composites (UHTCC) with significant strain capacity and high toughness is expected and potentially utilized to improve the performance of engineering structures under complex loadings. This study discusses the triaxial compressive behavior of UHTCC tested under seven different confining pressures with the maximum normalized confining pressure reaching 0.51. The obtained results indicate that the devia-toric strength, peak axial strain and peak lateral strain of UHTCC increase substantially with increasing confining pressure. Among these, the peak axial strain-confining pressure curve exhibits a clear nonlinear increasing trend. For the stress-strain curves, almost no softening phenomenon was observed when the normalized confining pressure reached only 0.425. The William-Warnke and Power-Law failure criterion are found suitable for describing the triaxial characteristic. The toughness index well reflects the significant energy absorption capacity of UHTCC. Based on the experimental results, UHTCC is expected to perform well in important civil and military engineering application which is potential to resist multi-axial loadings.