Effects of Pore Fluid’s pH on the Physico-Mechanical Behavior of High Plasticity Silt

Abstract

Acid rain and water pollution are alarming threats, necessitating the study of their influences in different envi - ronmental aspects. This study investigates the effects of pore water’s pH on the behavior of high plasticity silt. Samples with varied pore fluid pH were tested for Atterberg limits, unconfined compressive strength on the 9 th , 18 th , and 27 th curing days. Particle size distribution and zeta potential were assessed on the 27 th day on strength tested samples. The test showed that the soil properties change with the pH of the pore fluid and the days the sam - ple were cured for. The particle size distribution revealed that higher silt and clay fractions were present in acidic and alkaline conditions respectively. Liquid limit varied irregularly with different pH conditions. On all test days, the plastic limit increased under acidic and alkaline conditions compared to neutral conditions. The Unconfined compressive strength and zeta potential were observed to be low in the acidic and alkaline conditions compared to the neutral condition. The result infers that the dissolution of cementitious elements in acidic and alkaline conditions reduces the long-term strength of the soil. These findings encourage geotechnical engineers to evaluate the pH characteristics of the pore fluids during geotechnical analysis.