Splitting tensile strength of recycled tire steel fiber-reinforced alkali-activated slag concrete designed by Taguchi method

Despite offering several benefits in terms of environment and economics, few studies were conducted on the ground granulated blast furnace slag (GGBFS) based alkali-activated concrete reinforced with recycled tire steel fibers (RTSFs). Therefore, this paper employed the Taguchi method to investigate and optimize the influence of GGBFS content, the alkaline solution to GGBFS content ratio, sodium hydroxide solution concentration, and RTSF volume fraction on splitting tensile strength (STS) of recycled tire steel fiber-reinforced alkali-activated slag concrete (RTSFR-AASC). The microstructural evaluation was done through scanning electron microscopy, and Fourier transform infrared spectroscopy (FTIR) analyses. The results indicated that the fiber content, the most efficient parameter on STS, led to a considerable enhancement in the performance characteristic. Microstructural analysis proved the variations in formation of C-S-H gel. The results of the confirmation experiment on the proposed optimized RTSFR-AASC mixture with the highest 28-day STS (7.11 MPa) confirmed the effectiveness of the Taguchi method.