Split tensile strength of slag-based geopolymer composites reinforced with steel fibers: Application of Taguchi method in evaluating the effect of production parameters and their optimum condition

In the present study, split tensile strength of slag based geopolymer composite reinforced with steel fibers has been designed by Taguchi method. In this ceramic matrix composite, furnace metallurgical slag of rockwool acts as an aluminosilicate source. Four main parameters including water curing regime, sodium hydroxide concentration, alkali activator to cement weight ratio and steel fibers weight percent, each at three different levels, were considered for examination. A total number of 9 experiments were performed according to L9 array which was proposed by the Taguchi method. The obtained results were evaluated by analysis of variance (ANOVA) method to determine the optimum level of each factor. ANOVA revealed that specimen with curing regime of 14 days, sodium hydroxide concentration of 14 M, Alkali activator to cement weight ratio of 0.24 and steel fibers with 5 wt% was potential of highest strength (8.87±1.71 MPa) in considered procedure. Based on achievements, it is possible to produce high strength geopolymer composite reinforced with steel fibers. Also, it was shown that split tensile strength of slag based geopolymer composite reinforced with steel fibers could be suitably designed by the Taguchi method.