Investigating the impact of travertine powder on strength and permeability of swelling clay

Abstract

Stabilization of swelling soils with high volume change potential is an important topic in geotechnical engineering because irreversible and catastrophic damages will occur if they are not appropriately managed. This study aimed to determine the effect of travertine powder on the swelling, strength, and permeability properties of weak and swellable soils. Within the scope of the study, soil improvement performance of travertine powder, which can be used as a soil improvement tool, was analyzed in detail, and the effect of travertine powder on the hydraulic and strength properties of the soil was discussed comparatively. Waste powder from travertine quarries taken from Eskipazar (Turkey) and Bentonite clay with high swelling potential taken from Tokat (Turkey) was used in the study. Samples were prepared by adding 10%, 20%, 30%, and 40% by weight of travertine powder to the Bentonite, and these mixtures were cured for 0-7-14-21-28-35 and 42-day periods. Unconfined compressive strength test, direct shear test, swelling pressure, and permeability tests were then conducted on each of the cured-stabilized samples. While the permeability coefficient, unconfined compressive strength, cohesion, and internal friction angle of bentonite samples with the additive increased over the curing time, the swelling pressure value decreased. The addition of travertine led to a substantial enhancement in the unconfined compressive strength (by 35%), internal friction angle (by 350), and cohesion (by 26%), while simultaneously reducing the swelling pressure by 58%. These findings emphasize that travertine powder enhances weak and swellable soils, offering an eco-friendly and cost-effective solution for improving engineering properties.