Development and assessment of eco- and user-friendly geopolymeric stabilizers for sustainable soil improvement

Abstract

This paper presents an innovative approach to address inherent limitations in traditional geopolymerization methods by focusing on producing eco and user-friendly mechano-chemically activated geopolymeric (M-GP) stabilizers for soil stabilization applications. A comparative analysis is conducted to benchmark the effectiveness of these stabilizers against conventionally activated geopolymer (C-GP) stabilizers. The study also investigates the influence of ground granulated blast furnace slag (GGBFS) amount on the mechanical and durability characteristics of stabilized soil specimens. Furthermore, the effect of activation techniques on the efficacy and strength of soil after sulfuric acid (H₂SO₄) exposure was investigated. The durability performance was evaluated by submerging the samples in a 1 % H₂SO₄ solution for a period of 60 and 120 days. The evaluation addresses various aspects such as visual appearance, mass changes, unconfined compressive strength (UCS), ultrasonic pulse velocity (UPV) and the Fourier transform infrared spectroscopy (FTIR) of geopolymer-stabilized soil samples. Results indicate that the UCS of M-GP samples surpassed C-GP-stabilized soil by 12–45 %. Moreover, the geopolymer-stabilized soil exhibited a significant increase in strength, with improvements of 114 %, 247 %, and 361 % observed at GGBFS content levels of 50 %, 75 %, and 100 % by weight, respectively. After exposure to the H₂SO₄ solution, M-GP-stabilized soil demonstrated superior resistance to sulfuric acid compared to C-GP-stabilized soil. The residual ultimate compressive strength (UCS) for M-GP and C-GP specimens was 80 % and 76 % respectively after being subjected to the H₂SO₄ solution for 60 days. However, these values further declined to 53 % and 48 % after 120 days of exposure. In addition, the result showed that geopolymer-stabilized soil containing 75 % slag exhibited superior resistance to H₂SO₄ compared to other stabilized soil samples.