New models for predicting workability and toughness of hybrid fiber reinforced cement-based composites

The new models using reinforcing index to predict workability and toughness of hybrid fiber reinforced cementitious composites (HyFRCC) were systematically studied in this paper. The existing models are discussed and new quadratic function models are proposed. A Rl(v) considering elastic modulus of fibers is employed to calculate the workability parameter of fresh HyFRCC, and the analysis indicates that the slump cone, V funnel, J-Ring and L-Box test results can all be predicted by this workability model. In addition, a Rlv considering tensile strength of fibers is employed to calculate the toughness of harden HyFRCC. The analysis indicates that this toughness model can be used to predict the compressive toughness, flexural toughness, equivalent flexural strength (according to JCI-SF4), I-5, I-10 and I-20 (according to ASTM C1018) of HyFRCC, without considering the matrix (mortar or concrete) and fiber combination (e.g., steel-polyvinyl alcohol fiber-whisker, steel-cellulose fiber, steel-polypropylene fiber and so on). The new models have extensive applicability and good correlation with experimental results, which can help offering good behaviors to HyFRCC fresh mixtures, even hardened states, in design and construction practice via fiber mix optimization. (C) 2018 Elsevier Ltd. All rights reserved.