Investigating and optimizing the mix proportion of pumping wet-mix shotcrete with polypropylene fiber

In order to obtain the optimum mixture proportions of wet-mix shotcrete, the tests of shotcrete properties with different fiber length were firstly conducted and the situation of breakage fiber was analyzed statistically. Secondly, mix proportion factors of wet-mix shotcrete were analyzed by using the Taguchi method. Results showed that increasing fiber length enhanced the shear and tensile failure of fibers. According to the analysis of variance (ANOVA), the water/binder (W/B) ratio was the most effective parameters on the slump and compressive strength, whereas the polypropylene fiber (PF) was the dominant factor on the splitting tensile strength and water permeability. Finally, based on the multi-factor comprehensively considering, the final mix design was determined. (C) 2017 Elsevier Ltd. All rights reserved.