An Effect of Sodium Polyacrylate on Sandy Soil Parameters and Its Use in Soil Improvement

Abstract

Superabsorbent polymers, which swell into gel form when in contact with a liquid, can absorb hundreds of times their own weight in water. They have different application areas such as agriculture, drug delivery, cleaning, and cosmetics. In this study, the effect of sodium polyacrylate on the basic sandy soil parameters and its use in soil improvement applications against liquefaction were evaluated as a new approach. Sodium polyacrylate was used by mixing with cement at an optimum rate around 25.00% by weight, since gel form releases back water if exposed to load. To examine the effect of sodium polyacrylate-cement gel on the mechanical properties of sandy soil, shear box and permeability tests were performed by mixing the gel with the soil in four different ratios. In addition, the changes that occur as a result of the improvement were investigated in following cases; horizontal layer, vertical layer, mixed with soil and column application with different spacings. Due to the increase in gel content, the permeability values decreased and the shear strength increased more than two times. In the experiments conducted with the shaking table, the soils were exposed to dynamic effects after the application of the mixture within the purpose of elimination the liquefaction problem. It was concluded that the observed settlements on the soil surface decreased between 25.90% and 92.60% thanks to the improvement applications. In addition, a reduction level up to 39.00% occurred in the pore water pressure. Finally, the usability of sodium polyacrylate-cement mixture is proven to enhance the properties of sandy soil.