Stabilisation/Solidification of the Zn-Contaminated Loess Silt in View of the Mechanical Properties

Abstract

The effectiveness of the stabilisation/solidification process depends upon a number of factors, the most significant of which are the type of binder, contaminants, and soil undergoing treatment. In accordance with the principles of sustainable construction, alternatives to cement are sought after, with the objective of achieving the lowest environmental impact while maintaining a high level of strength and effective binding of the contaminant. In the study of the stabilisation/solidification of zinc-contaminated loess, incinerated sewage sludge fly ash with reactive magnesia was selected as the binder, and the UCS of the mixtures and microstructure was verified after 28 days of treatment. The values obtained were related to the strength of a reference sample and exhibited by S/S products using Portland cement. The findings verified the effectiveness of the selected materials in the S/S process. Following a 28-day treatment with 30 and 45% IFA and MgO in a 2:1 ratio, the samples were classified as a hard subgrade, suitable for civil engineering purposes, due to the UCS values achieved, ranging from 0.52 to 0.9 MPa. Furthermore, a correlation between the UCS values and the water content was identified, and the mineralogical composition of S/S products was determined with the use of the XRD technique.