Properties of cement–bentonite mortar developed by mineral additives for primary firm secant pile by Taguchi method

Abstract To make construction materials more sustainable and greener, companies must consider the environmental impact when sourcing materials include developing methods for sustainable recycling and encouraging design practices that prioritize the use of green materials using additives. Geotechnical applications including construction of cutoff walls require development of enhanced materials that possess certain attributes to ensure strain compatibility with surrounding soil. The study aims to explore the utilization of different materials such as bentonite, cement dust, fly ash, lime and polypropylene fibers to produce cement–bentonite mortar with low permeability and sufficient strength. For optimizing the process parameters in the experimental domain, an orthogonal array by Taguchi method was used, and thirty-two experimental runs were performed. The properties investigated included flow%, displaced volume rate, compressive, splitting tensile, flexural, shear strengths, elastic modulus and permeability coefficient. The test results demonstrated that cement dust, fly ash and lime could achieve optimal performance in terms of low permeability and sufficient strength. Additionally, polypropylene fibers up to 0.3% could be effectively used to achieve sufficiently low elastic modulus without affecting other conductive strengths significantly. The findings of the regression model demonstrated that the developed models could account for how the independent variable affected the necessary responses. This study could provide engineers with insights into selecting the appropriate materials to achieve the desired performance characteristics for some geotechnical applications considering sustainability.