| Abstrakt: |
In order to achieve the resource utilization of beach silty soil and industrial wastes, and quantitatively optimize the critical factors of geopolymer cured silty soil, the mix ratio of alkali-activated slag-fly ash based geopolymer cured silty soil was optimized based on the Box-Behnken response surface method. The slag content, alkali activator modulus and alkali activator content were selected as the main factors to be investigated, and the curing mechanism was analyzed by combining the macroscopic properties and microscopic morphology. The results show that: the optimum mix ratio of cured soil is slag content 86.5% (mass fraction), alkali activator modulus 0.84, alkali activator content 7.3% (mass fraction), the unconfined compressive strength of cured soil at 7 and 28 d under the optimum mix ratio is 5 823 and 7 027 kPa, respectively. The prediction value has a small error with the actual value, and the established model is accurate and reliable in fitting the actual data. The hydration products of cured soil are mainly amorphous gel hydrated calcium silica-aluminate (C-(A)-S-H) and silica-aluminate polymer (N-A-S-H), which enhance the densification and skeletal structure of soil body, thus improving the strength of cured soil. This study provides a theoretical basis and experimental foundation for alkali-activated geopolymer cured silty soil. [ABSTRACT FROM AUTHOR] |
