Volume 44, N. 1

January-March 2021

Stiffness, compressibility, and hydraulic conductivity of compacted soil mixtures submitted to acidic percolation

Technical Notes

Volume 44, N. 1, January-March 2021 | PDF (10 downloads)

Abstract

The inadequate disposal of hazardous solid waste has become a potential issue, mainly because of the impacts on the environment and human health. This occurs mainly through the contamination of subsurface soil and groundwater by leachates, which are often of the acidic constitution. To prevent such situations, the study of more efficient waste containment techniques has become opportune. In this way, this work was aimed to investigate the mechanical and hydraulic behavior of compacted clayey soil, with and without the addition of Portland cement (0 and 2%), submitted to the action of a sulfuric acid solution (2% volume concentration) and to a constant static vertical load (280 kN/m² ), aiming at its prospective application as containment barrier. The experimental program comprised a few tests performed in an instrumented rigid-wall permeameter, during which the variations in hydraulic conductivity, shear modulus, and settlements were measured. The results showed that the hydraulic conductivity increased with cement addition when only water was percolated. During the acidic percolation, however, a reduction was observed only for the cemented soil. The acidic attack caused, almost instantaneously, an increase in the settlement rate and a reduction in stiffness, although a trend of stabilization was observed afterward.        

Keywords: Contaminant barriers with and without cement, Long-term hydraulic <, br />, conductivity, Bender element test,


Submitted on February 24, 2020.
Final Acceptance on December 30, 2020.
Discussion open until May 31, 2021.
DOI: 10.28927/SR.2021.047720