Improvement of Expansive Soil by Using Silica Fume

Abstract

Expansive soils are characterized by their considerable volumetric deformations representing a serious challenge for the stability of the engineering structures such as foundations. Consequently, the measurements of swelling properties, involving swelling and swell pressure, become extremely important in spite of their determination needs a lot of time with costly particular equipment. Thus, serious researches attempts have been tried to remedy such soils by means of additives such as cement, lime, steel fibers, stone dust, fly ash and silica fume. In this research the study of silica fume has studied to treatment expansion soil, the clay soil was brought from Al-Nahrawan in Baghdad. The soil selected for the present investigation prepared in laboratory by mixing natural soil with different percentages of bentonite (30, 50 and 70% by soil dry weight). The test program included the effect of bentonite on natural soil then study the effect of silica fume (SF) on prepared soil by adding different percentage of silica fume (3, 5, and 7 by weight) to the prepared soils and the influence of these admixtures was observed by comparing their results with those of untreated soils (prepared soils). The results show that both liquid limit and plasticity index decreased with the addition of silica fume, while the plastic limit is increase with its addition. As well as, a decrease in the maximum dry unit weight with an increase in the optimum water contents have been obtained with increasing the percentage of addition of the silica fume. It is also observed an improvement in the free swell, swelling pressure by using silica fume. It can be concluded that the silica fume stabilization may be used as a successful way for the treatment of expansive clay.

The Effect of Utilizing Silica Fume and Eggshell Ash on the Geotechnical Properties of Soft Kaolin Clay

“…Based on the results obtained in Figure 3, both of the stabilizers can bind and flocculate the kaolin to become coarser particles, with a reduction of fine clay content via the cation exchange activity and pozzolanic reactions. These outcomes are similar to the previous studies conducted by other researchers, aforesaid in the previous section and paragraph [34]. The diminution in PI upon the addition of SF and ESA shows that the expansive characteristics of kaolin clay are reduced.…”

Effect of Silica Fume as a Waste Material for Sustainable Environment on the Stabilization and Dynamic Behavior of Dispersive Soil

“…In the literature, different studies were conducted to evaluate the effect of silica fume on problematic soils [38][39][40][41][42]. In these studies, the performance of swelling and dispersive soils treated with SF is evaluated in terms of the strength properties, mostly in the static state, together with the change in their geotechnical index properties.…”

Effect of Silica Fume on the Shear Strength of Cohesionless Soil

“…The results plotted in Fig. (11) And table (3) Are listed in indicate that, the higher the normal stress the lesser of horizontal displacements. The relationship between the pull out force and the induced horizontal displacement is not in a linear relationship; when the applied pull out duplicated to four times i.e.…”