Research of Geopolymer Deal with the Strength of Soft Soil and Microstructure Test

Abstract

This paper aims at a highway that adopted geopolymer processing the strength of soft soil foundation engineering in Wenzhou city, Zhejiang province. The paper discussed the influencing factor of geopolymer soil’s mechanical strength by orthogonal optimization test and microstructure test, and obtained the primary factors that affect change laws of geopolymer soil strength as well as the reasonable blending ratio of geopolymer variation. It considered the best ratio of geopolymer to soil of geopolymer reinforced soft soil is 14%, at the same time this paper found that the unconfined compressive strength of geopolymer is reduced with the increasing of soft soil’s plasticity index through different plastic index of geopolymer soft soil strength test. Experiments also showed that the relation of reinforced soil sample’s shear strength and compressive strength expressed as positive relationship. internal cohesion and angle of internal friction are enhanced with the increasing of compressive strength within limits, the relation of shear strength and compressive strength is $\tau = 0.25fcu$. Scanning electron microscope (SEM) sweeping test indicated that geopolymer produced cementation and filling to soil after reacting; Computed tomography (CT) sweeping test indicated that geopolymer could decreased the pore of soil and reduced porosity. This paper provided scientific evidence for substantial project that adopted geopolymer to treat soft soil foundation.