Experimental Investigation on Microhydration and Micromechanical Properties of Cement-Sandy Soil Mixtures Reinforced with Cotton/linen-blended Fiber

The micro-hydration degree plays a significant role in the strength of cement-sandy soil mixtures. The present study used cement-fiber-sandy soil mixtures in which the fiber was sourced from waste cotton/linen-blended fabric to investigate the impacts of different levels of fiber content on the hydration mechanisms and micromechanical performance. Experiments using scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) were carried out to determine how the component content of the different constituents changed with the fiber content (0%, 0.5%, 1.0%, and 1.5%) during the microhydration of the mixtures. A comparative analysis of the strength characteristic curves and the tensile strength variations for different groups of reinforced cement-sandy soil mixtures were conducted by performing triaxial shear tests. The results show that the peak unconfined compressive strength of the mixtures gradually increases with the quartz content of the matrix. The compressive strength of the matrix reaches a peak of 1.5938 MPa, an increase of 24.17%, when the cement and fiber contents were 3% and 1.5% (weight), respectively, with a fiber length of 9 mm. This paper has reference values for the green reinforcement of cement-sandy soil mixtures in the development of underground space.