Investigation into the Effect of Nanomaterial Injection on Improving the Geotechnical Properties of Granular Soils

The overall objective of the current study is to evaluate the effect of nanomaterial injecting on the geotechnical properties of granular soils. In this laboratory study, using a injecting method to improve the geotechnical properties of granular soils, cement (C), selected as the main material for mortar grouting, was injected into a soil of poorly granulated grains with relative densities (D-r) of 30% and 70%, along with the following materials: nano-silica (NS) and nano-aluminum oxide (NA) with values of 0.9%, 0.6%, and 0.3%; silica fume (SF), 5% by weight of the cement; and water-to-solid ratios (w/s) of 1, 1.4, and 1.8. Experiments testing the uniaxial strength of the mortar, sedimentation, viscosity, permeability, and unconfined compressive strength were performed on the samples. The results indicated that in both relative densities, the use of nanomaterials increased the compressive strength and decreased the permeability of the samples. The effect of silica fume on reducing permeability was also found to be significant. Addition of nanomaterials to cement reduced the sedimentation rate and the setting time of primary and secondary mortar and had a positive effect on increasing the uniaxial strength and viscosity of mortar.