The investigation on mechanical properties of ultra-high toughness cementitious composite using orthogonal experiment

Ultra-high toughness cementitious composite (UHTCC) exhibits excellent deformability and multiple cracking properties under tensile loading, which are subjected to multiple compositional parameters. This paper simultaneously investigated the effects of water to binder ratio (W/B), cement and silica fume to fly ash ratio (CS/F), and amount of expanded perlite powder (EPP) on the mechanical properties of UHTCC using the orthogonal experiment, with compressive strength and tensile properties. The result of range analysis presented that the order of the influence of factors on mechanical indexes was CS/F > W/B > EPP. An increasing CS/F was conducive to the strength. Conversely, a lower CS/F had a beneficial effect on the tensile performance. In addition, the best level (within limited levels in this study) of each factor on indexes was carried out. The consequence of analysis of variance showed that W/B and CS/F had significance on the compressive strength and CS/F was a crucial factor in applications with lower crack width required, such as waterproof engineering. The comprehensive analysis indicated that the combination of W/B = 0.3, CS/F = 4:6, and EPP = 23.3 g/L was recommended for general mechanical properties of UHTCC.