Swelling prediction for green stabilized fiber-reinforced sulfate-rich dispersive soils

Sulfate-rich dispersive soils are a major concern due to their high susceptibility to erosion and heave, related to high amounts of adsorbed Na⁺ ions and the formation of expansive minerals derived from reactions involving sulfates and calcium, respectively. In this sense, the development of alternative treatments to overcome such problems must be sought, since the application of lime and/or Portland cement by themselves has proven to be ineffective. Thus, the present paper proposes a binder composed of carbide lime and ground glass waste combined with fiberglass reinforcement to stabilize such soils. The efficiency of the proposed alternative towards reduction of swelling was assessed through 3-D volumetric swell tests carried out on compacted soil-binder-fiberglass blends molded with multiple different dosages. The results have shown that the porosity and the amount of carbide lime influenced the volumetric strain (ε_v) of the tested specimens greatly. The influence of porosity was inversely proportional, while the influence of the amount of carbide lime was directly proportional. The addition of fiberglass was shown to be ineffective. Thus, the ε_v was successfully correlated to the adjusted porosity/lime index (η/L_iv), proving the innovative character of the approach applied herein and enabling the prediction of the ε_v for different dosage options.