Effect of sodium silicate on the properties of loess stabilized with alkali-activated fly ash-based

It is a common way to prepare geopolymers by sodium silicate alkali activating fly ash. In this paper, the effects of sodium silicate with different moduli and Baume degrees on the engineering properties and microstructure of loess solidified by alkali -activated fly ash-based geopolymers were studied by unconfined compressive strength test, direct shear test, disintegration test, BET tests and water absorption test. The conclusions are as follows: As the modulus decreases and the Baume degree of sodium silicate increases, the optimal moisture content of the loess decreases, the maximum dry density, the compressive strength and cohesion increases. The lower the sodium silicate modulus and the larger the Baume degree are, the weaker the disintegration of the geopolymer-solidified loess, the lower the natural water absorption and saturated water absorption, the smaller the average pore diameter, the larger the specific surface area of pores and the larger the nanos scale pore volume are. (C) 2021 Published by Elsevier Ltd.

Automated summary

Lower sodium silicate modulus and higher Baume degree lead to decreased optimal moisture content, increased maximum dry density, compressive strength, and cohesion of loess solidified by alkali-activated fly ash-based geopolymers. Additionally, these conditions result in weaker disintegration, lower natural water absorption, saturated water absorption, smaller average pore diameter, larger specific surface area of pores, and larger nanoscale pore volume in the geopolymer-solidified loess.