Sustainable engineering of fiber-reinforced geopolymer-treated low plasticity clay linking geomechanics and microstructure through support vector machines

The variations in soft soil exhibiting low plasticity often damage lightweight structures, costing billions annually. Although well-known traditional stabilizers are efficacious, their production can have a massive environmental impact. This paper investigates the geomechanical efficiency of low-plasticity clay reinforced with chemically treated banana fiber (CTBF) and EnviroSafe geopolymers, comprising alkaline solutions and industrial waste materials. The proportions of coal gangue ash (CGA) replacement with silica fume (SF: 0–20%) were varied in the alkaline solution by maintaining a 0.4 water-to-solid ratio. A series of consolidation, compression, shear, and penetration resistance tests were performed to determine the geomechanical properties. In addition, Stereoscopic, Fourier-transform infrared (FTIR) spectroscopy, and Thermogravimetry analysis (TGA) tests were conducted at varying CTBF-SF mixture dosages. The study demonstrated a substantial improvement in the strength characteristics of CGA-SF in geopolymer-stabilized low-plasticity clay. The results of SF (> 10%) in CGA-based geopolymer stabilizer soil attained the lowest equilibrium void ratio over the unreinforced soil. Furthermore, a support vector machine (SVM) algorithm model was proposed to predict the geomechanical strength of fiber-reinforced alkaline soil, and the results showed an excellent predictor of geomechanical strength performance.