Experimental and statistical analysis of soil stabilization to avoid landfilling

Clayey soil is a moisture-sensitive material whose properties pose geo-environmental challenges in the construction sector. Soil stabilization through lime treatment offers advantages using local unsuitable soils without landfilling. This study investigates lime treatment and stabilization of sensitive reddish clay soil from the Setif region, Algeria. Geotechnical, chemical, and physic-chemical characterizations of the clayey soil with different percentages of dry lime (i.e., 0% to 9% by weight with intervals of 3%) were conducted. The standard plasticity test shows that the lime treatment causes a decrease in the plasticity index (from 30.7 to 22.1%) and methylene blue value (from 5% to 2.71%). Furthermore, the compressive strength test revealed a 16-fold increase in unconfined compressive strength (UCS) after 28 days with 6% lime (130 kPa vs 2100 kPa). However, a decrease in dry density was also observed (16 kN/m3 vs 15.7 kN/m3). Chemical and physic-chemical analyses using X-ray fluorescence and diffraction revealed the appearance of other chemical elements and mineral phases. Finally, ANalysis Of VAriance (ANOVA) was used to evaluate the effect of curing time and lime content on UCS. Both variables affected the strength development positively. The lime content, on the other hand, was two times more efficient than the curing time.