Suitability of Slag-Based Geopolymer Stabilized Expansive Soil as a Pavement Material

Abstract

This study examines the efficiency of geopolymer-stabilized expansive soil as a pavement layer. For this, expansive soil (ES) is treated with different fractions of alkali-activated slag geopolymer. The slag of 5%, 10%, and 20% (by dry weight of soil) was activated with 2 M, 6 M, and 8 M sodium hydroxide solution (NaOH), respectively. With 20% slag and 8 M NaOH, the plasticity index and swell potential were reduced by 80.76% and 83.63%, respectively. The stabilized ES with 5%, 10%, and 20% slag attained a 28-day UCS of 2.1 MPa, 3.45 MPa, and 5.19 MPa, respectively. Further, the effect iveness of the stabilized mix as base course material was assessed using a finite element model of a two-layered pavement system under two different axle wheel loads. The obtained deformations conclude that the stabilized base course material has a superior performance compared to conventional granular materials.