Field case study of soil columns mixed with wood pellet fly ash blended binder in weathered granite soils

This study investigates the influence of wood pellet fly ash blended binder (WABB) on the mechanical properties of typical weathered granite soils (WS) under a field and laboratory tests. WABB, composed of 50 % wood pellet fly ash (WA), 30 % ground granulated blast furnace slag (GGBS), and 20 % cement by dry mass, was applied at dosages of 200–400 kg/m 3 to four soil columns were constructed at a field site deposited with WS. After 28 days, field tests, including coring, standard penetration tests (SPT), and permeability tests, revealed enhanced soil cementation and reduced permeability, indicating a denser soil matrix. Unconfined compressive tests (UCT) and free-free resonant column (FFRC) tests on field cores at 28 and 56 days, compared with laboratory specimens and previously published data, demonstrated strength gains 1.2–2.1 times higher due to field-induced stress. The presence of clay minerals influenced the WABB's interaction and microstructure development. Correlations between seismic waves, small-strain moduli, and strength were developed to monitor in-situ static and dynamic stiffness gain of WABB-stabilized weathered granite soils. • Performance of wood pellet fly ash blended binder in soil columns are presented. • Coring, SPT, and permeability tests assess mechanical properties of stabilized soils. • Free-free resonant column test evaluates strength and stiffness development. • Stabilized soils exhibit 1.2–2.1 times greater field strength than laboratory results. • Seismic velocity and strength models are proposed for in-situ monitoring.