Optimization of strength and durability properties of rubberized concrete mixtures containing silica fume using Taguchi method

The present study aims to optimize the mixture design of rubberized concrete using the Taguchi method to enhance various performance parameters, including workability, compressive and flexural strengths, dry unit weight, water absorption, and resistance to sulfate and HCl acid exposure. Three primary control factors were investigated including silica fume, fine rubber, and coarse rubber. Each factor was evaluated at four substitution levels: 5 %, 10 %, 15 % and 20 % silica fume; 2.5 %, 5 %, 7.5 % and 10 % fine rubber; and 2.5 %, 5 %, 7.5 % and 10 % coarse rubber. A total of 16 mixtures were prepared and evaluated. The experimental results demonstrate the effects of these factors on concrete characteristics, with a focus on identifying optimal proportions that achieve enhanced mechanical strength and durability characteristics. Additionally, to maximize compressive strength, flexural strength, and resistance to sulfate and HCl attacks; the application of the Taguchi method proposed an optimized mixture design comprising 15 % silica fume, 2.5 % fine rubber and 2.5 % coarse rubber. The optimized mixture showed improvements in 28-day compressive strength, 56-day compressive strength, 28-day flexural strength, resistance to Na₂SO₄ and resistance to HCl of 4.55 %, 4.92 %, 5.34 %, 5.22 %, and 5.96 %, respectively.