Application of a Soft Soil Stabilized by Composite Geopolymer

Abstract

As a new type of green material, the geopolymer has good engineering technical properties, outstanding sustainable development performance, and huge market potential. It also has significant performance advantages and economic benefits for soft soil foundation reinforcement. In this study, in order to explore the variation law of the strength of geopolymer reinforced soft soil under different geopolymer contents (the mass ratio of geopolymer to soft soil), age, and mixing time, a three-factor and three-level orthogonal test was designed, and a direct shear test and unconfined compressive strength test were carried out. It is found that the strength of geopolymer-reinforced soft soil increases with the increase of the geopolymer and with the growth of the age under the same geopolymer content. When the geopolymer content is 14%, the geopolymer has the best effect in reinforcing the soft soil. It is proven by scanning electron microscopy (SEM) and computed tomography (CT) scanning that the formation of gelatinous zeolite precursors in the stabilized soil makes the stabilized soft soil tend to have a uniform and dense microstructure. The infrared spectrum of geopolymer stabilized soil is mainly asymmetric tensile and compressive vibrations of Si-O-Si and Al-O-Si bonds and tensile vibration with an Si-O or Al-O bond. The test results of the field test section showed that the geopolymer mixing pile had a good effect, which provided a new idea for the treatment of a soft foundation.