Stabilization of Loess Using Nano-SiO2

Abstract

Improving the performance of loess is of significant importance for lowering its collapsibility and water sensitivity to construction requirements and for geohazard mitigation. The present paper studies the changes in mechanical, structural, and mineralogical properties of nano-SiO2-treated loess with different contents and curing days. The mechanical behavior was examined by unconfined compressive strength (UCS) of untreated and treated loess. To better understand the mechanisms of stabilization, particle size distributions, scanning electron microscope (SEM) images, and X-ray diffraction (XRD) analyses were carried out. The results show that the UCS increase with increasing contents and curing days due to nano-SiO2 addition produced coarser particles, denser packing, and smaller pores in treated loess. The changes in the properties can be attributed to the formation of aggregation and agglomeration, with greater particle sizes and more interparticle contact. In addition, the results from mineralogical component analysis further confirm that physical structure modification controls the changes in mechanical and fabric properties, rather than chemical component alteration. Even small nano-SiO2 additions can also provide great improvement when curing days are enough for the treated loess. These findings reveal that nano-SiO2 has the potential to serve as a cost-effective stabilized additive that treats the universal loess.

A Clay-Based Geopolymer in Loess Soil Stabilization

“…Geopolymer can be synthesized by mixing calcined kaolin and strongly alkaline solutions (such as NaOH or KOH) and then curing at a room temperature [10]. Several studies have examined the use of various geopolymers for loess soil stabilization, including fly ash, lime, and cement, etc., [11][12][13][14][15][16]. However, the use of the anhydrous calcined form of the clay mineral kaolinite (metakaolin) was given less attention in loess stabilization.…”

“…Loess is a widespread surface deposit in many parts of the world. There is a strong need for loess stabilization in construction requirements and geohazard mitigation due to its propensity to collapse and subsidence after loading and wetting [11,12]. Moreover, unpaved roads in loess are associated with strong erosion by wind and water, which leads to soil disintegration [7].…”

Study on the Mechanism of Nano-SiO2 for Improving the Properties of Cement-Based Soil Stabilizer

“…Shafiq [22] and Murthy et al [23] discussed the influence of nano-SiO 2 on the mechanical properties and durability of concrete. Kong et al [24] found that nano-SiO 2 could effectively improve the unconfined compressive strength of loess and improve pore structure. The above explorations have enriched the research on the improvement of the properties of soil stabilizers, but generally speaking, compared with the broad application prospects showed by soil stabilizers as materials for efficient utilization of soil and water resources, the current research status still needs to be deepened.…”

Impact of Biocompatible Nanosilica on Green Stabilization of Subgrade Soil

“…Specifically, fly ash, cement and lime are leading inorganic additives used in the soil stabilization. Due to their calcium-based structure, they frequently endure chemical reactions with the soil in the presence of water resulting in an overall improvement of the soil physicochemical properties 11 . Among these additives, fly ash owing to cost-effectiveness and abundance, dominantly attracts more consumers rather than lime in the construction industry.…”