Characterization of volume change and strength behavior of micro-silica and lime-stabilized Cyprus clay

Abstract

This study aims to assess the suitability of micro-silica (MS) as an industrial waste to modify the hydro-mechanical behavior of expansive soil in comparison with the use of lime as a traditional stabilizer. Due to limitations associated with soil treatment with calcium-based materials, the effect of lime-micro-silica (LMS) on stabilization of expansive clay was also studied with the aim of reducing the amount of lime consumption. The clay was stabilized with different percentages of lime alone (3% and 5%), MS alone (10% and 20%) and mixtures of LMS (3-10%, 5-10%, 3-20% and 5-20%). Experimental study performed on treated and untreated specimens included the reactivity tests measuring the pozzolanicity of the additives, compaction characteristics and Atterberg limits of mixtures, one-dimensional swell, compressibility, shrinkage, unconfined compressive strength of compacted specimens of different mixtures, as well as X-ray diffraction, scanning electron microscopy and wet chemistry analysis to study the mineralogy, microstructure and chemical composition of specimens. The results showed that the addition of MS alone did not have a significant effect on the stabilization of expansive soil, whereas stabilization with LMS achieved promising results with 10% MS ? 3% lime mixture, hence achieving the goals of recycling MS as well as minimizing the amount of lime used. This combination was effective in improving the hydro-mechanical behavior of the clay due to formation of cementitious compounds resulting from pozzolanic reactions between Ca 2? of lime and SiO 2 of micro-silica.

Evaluation of the Permeability of Clay-Lime Mixtures for Hazardous Waste Insulation Barriers, Case of Southern Algeria (Adrar)

“…All the MDD values range from 17.7 to 17 KN/m 3 . This result is perfectly consistent with previous works [43,83,97,[102][103][104][105][106][107][108]. This decrease can be explained by the fact that lime tends to absorb water to complete its hydration, as well as the pozzolanic reaction [20,80,96,108].…”

“…It is noted as an immediate improvement of the workability and mechanical resistances, translated by a reduction of the plasticity marked by a lowering plasticity index (PI). This result seems identical to the data in the literature [43,[81][82][83]93,102,105,107,[109][110][111][112]. This decrease is due to a pozzolanic reaction that occurs when the pH of the soil solution becomes higher which is caused by the addition of (OH)ions to the soil [102,113].…”

“…This result seems identical to the data in the literature [43,[81][82][83]93,102,105,107,[109][110][111][112]. This decrease is due to a pozzolanic reaction that occurs when the pH of the soil solution becomes higher which is caused by the addition of (OH)ions to the soil [102,113]. Some authors note that the extent of plasticity changes depends not on the curing time but on the amount of lime added [93,114,115].…”

Effects of Mellowing Practice on the Strength and Swelling Properties of Road Construction Materials: Case of Sulphate-Bearing Clay Soils Stabilised with Lime-Silica Fume Blended Binder

“…Extensive studies showed that using silica fume (SF) as a blend to lime and an alternative to GGBS could be a promising and encouraging binder to suppress swelling without compromising compressive strength. However, its high cost and availability have often dissuaded its usage [ 13 , 14 , 15 ].…”

Application of eco-friendly and smart materials in geotechnical engineering for subgrade stabilization: a review

“…In general, the stabilized soil is the composite material results from the chemical reaction takes place between the natural soil and stabilizing agent [4]. Generally, subgrade stabilization can be carried out with the help of conventional methods such as use of lime, cement and flyash [3]. In recent years, use of chemical additives such nano chemicals and nano materials was found to be more effective in case of subgrade stabilization.…”