Optimization of fly ash-based polyethylene fiber-reinforced engineered cement-free composites with low-density and ultra-ductility using Taguchi robust design method

Abstract

This paper presents an experimental and analytical investigation on the density and mechanical properties of fly ash-based engineered cement-free composites (F-ECFC) reinforced by polyethylene fiber. Three key factors, i.e., curing temperature, curing time, and fiber volume, were investigated to determine their prominent effects on the density, compressive strength, and tensile properties of F-ECFCs using the Taguchi robust design (TRD) method. The test results showed that the F-ECFCs had widely varying compressive strength and tensile properties according to the test variables. Interestingly, some mixtures showed higher tensile strength than compressive strength. Using ANOVA, curing temperature was the most pivotal parameter in terms of influencing the density, compressive strength, and tensile performance of the F-ECFCs. Furthermore, multiple regression analysis was adopted to acquire the optimal mixture of the F-ECFCs with low-density and ultra-ductility. The optimized F-ECFC showed a density of 1.6 g/cm3, a compressive strength of 25.9 MPa, a tensile strength of 8.3 MPa, and a tensile strain capacity of 11.0%.