improving the strength properties of sand using laponite, a promising nanoparticle

In this study, mixing laponite with sand to reduce the development of pore water pressure in the fully saturated conditions has been studied to evaluate the strength properties of sand. the study investigated the effect of laponite concentration and resting time in a series of triaxial tests. the results show that even a little amount of laponite can significantly decrease the pore water pressure generation in the sand–laponite specimens due to the good rheological property of transparent gel. the results show that the decrease in the pore water pressure generated in specimens with increasing laponite contents [i.e., 0.5, 1, 1.5, and 2% (mass/mass)] was 17, 22.5, 25, and 27 kpa, respectively. it was also found that the modulus of elasticity of the sand–laponite specimens is almost double than that of the pure sand. in addition, changes in the friction angle and cohesion of the sand–laponite specimens with the four laponite concentrations were examined using direct shear box tests for three different temperatures. it was found that the effect of temperature was more prominent at the lower laponite contents as compared with the higher laponite contents. microstructural imaging with scanning electron microscope was assessed in conjunction with the pore pressure generation mechanism. this study provides an elaborate explanation of the non-homogeneity of the sand–laponite mixture and novel insight into the improvement and modification of the sand strength properties in the presence of laponite under static loading. © 2022, iran university of science and technology.