Rock and Soil Mechanics ›› 2022, Vol. 43 ›› Issue (9): 2421-2430.doi: 10.16285/j.rsm.2021.6925

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Mechanical properties of slag-fly ash based geopolymer stabilized sandy soil

ZHANG Jin-jin1, 2, LI Bo1, 2, YU Chuang1, ZHANG Mao-yu3   

  1. 1. College of Architecture and Civil Engineering, Wenzhou University, Wenzhou, Zhejiang 325035, China 2. Wenzhou Key Laboratory of Intelligent Lifeline Protection and Emergency Technology for Resilient City, Wenzhou Institute of Technology, Wenzhou, Zhejiang 325035, China 3. School of Civil Engineering and Architecture, Taizhou University, Taizhou, Zhejiang 318000, China
  • Online:2022-10-24 Published:2022-10-31
  • Contact: LI Bo, male, born in, born in 1982, PhD, Professor, mainly engaged in teaching and scientific research in geotechnical engineering. E-mail: libo@wzu.edu.cn E-mail:414785467@qq.com
  • About author:ZHANG Jin-jin, male, born in 1991, Master candidate, Experimenter, mainly engaged in geotechnical engineering testing.
  • Supported by:
    the National Natural Science Foundation of China(51978531) and the Public Welfare Project of Zhejiang Province (LGG22E080006).

Abstract: Silicate cement as a conventional soil curing agent has problems of high energy consumption and high emissions, and researchers have been seeking a more economical and environmentally friendly alternative to cement. In this study, geopolymers based on ground granulated blast-furnace slag (GGBS) and fly ash (FA) were used to reinforce sandy soils, and the effects of different factors on the mechanical properties of geopolymer stabilized sandy soils were investigated by adjusting the type and ratio of exciter, slag-fly ash ratio, water-cement ratio, and curing conditions. The specimens were studied in depth by unconfined compressive strength (UCS) test, electron computed tomography (CT) analysis, and scanning electron microscopy (SEM). The results show that the GGBS-FA-based geopolymer can effectively improve the mechanical properties of the sandy soil; the reinforcement effect of the composite exciter is better than that of the single-component exciter; the low temperature does not significantly reduce the final mechanical properties of the geopolymer stabilized sandy soil, but only delays the polymerization reaction and structure formation; the alkaline environment promotes the strength of the geopolymer stabilized sandy soil; the acidic environment and prolonged exposure to air reduce the strength of geopolymer stabilized sandy soils.

Key words: geopolymer, stabilized sandy soil, unconfined compressive strength (UCS), microstructure