Effects of Industrial and Agricultural Recycled Waste Enhanced with Lime Utilisation in Stabilising Kaolinitic Soil

Abstract

Soft kaolin clay is a problematic soils encountered in various construction projects that lead to the implementation of soil stabilisation. On the other side, the massive production of industrial and agricultural waste currently presents a critical problem for the environment. However, the utilisation of industrial and agricultural wastes in altering the characteristics of kaolinitic soil can be considered as an ideal solution to enhance the characterisation of problematic soils in the field of construction. Therefore, this study examines the alterations of the engineering properties of soft kaolin clay by utilising silica fume as the industrial by-product and eggshell ash as the agricultural by-product enhanced with lime use. To assess the impact of silica fume, eggshell ash, and lime on the various characteristics of kaolinitic soil, a series of laboratory experiments containing Atterberg limits, specific gravity, compaction test, unconfined compression test, X-ray fluorescence, X-ray diffraction, sieve analysis, and field emission scanning electron microscope is carried out. In this study, 2%, 4% and 6% of silica fume, 3%, 6% and 9% of eggshell ash and lime and the optimal combination of SF, ESA with 3%, 6% and 9% of lime are usedand were cured for 1, 7, 14 and 30 days. The results present that the optimal utilization of silica fume, eggshell ash, and lime can alter the engineering characteristics of the soft kaolin clay by reducing the specific gravity, consistency limits, linearshrinkage, and maximum dry density, while increasing the value of shrinkage limit, and optimum moisture content. In terms of strength improvement, the highest unconfined compression strength was recorded when soft kaolin clay was treated with 6% silica fume, 6% eggshell ash and 9% of lime for four (4) different days of curing with a strength improvement of 81.03%, 82.46%, 88.49% and 88.74%. Therefore, this study concludes that optimal use of silica fume, eggshell ash, and lime can persistently alter the characteristics of kaolinitic soil and open the way to economical and sustainable materials in improving the problem soil.

Experimental investigations on physico-mechanical properties of kaolinite clay soil stabilized at optimum silica fume content using clamshell ash and lime

“…Therefore, it is perspicuous that the inclusion of CSA and lime into the SFSS emerged in a 72%-115% of instantaneous strength improvement of CSA, 27%-77% of instantaneous strength improvement of lime, 325%-451% of premature strength improvement of CSA, 62%-178% of premature strength improvement of lime, 345%-974% of matured strength improvement of CSA, 70%-225% of matured strength improvement of lime, 503%-1124% of retarded strength improvement of CSA, and 75%-353% of retarded strength improvement of lime. The results obtained are consistent with the findings reported by Zaini and Hasan 26 , 40 .

Figure 7 Percentage strength improvement of SFSS with CSA and lime content at different curing periods.

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“…CSA and lime facilitate the cohesion and aggregation of SFSS particles, resulting in a coarser texture. Similar findings were reported by Alrubaye et al 19 and Zaini and Hasan 26 , 40 , 46 .…”

“…The depletion in peak intensities of quartz and kaolinite in the stabilized kaolinite clay can be ascribed to the development of cementitious bonding. Previous studies conducted by Zaini and Hasan 40 have examined the behaviour of silica fume (SF), eggshell ash (ESA), and lime stabilizers in kaolinite clay. Zaini and Hasan 40 identified recurring crystalline clay minerals, including kaolinite, illite, smectite, and montmorillonite.…”

“…Previous studies conducted by Zaini and Hasan 40 have examined the behaviour of silica fume (SF), eggshell ash (ESA), and lime stabilizers in kaolinite clay. Zaini and Hasan 40 identified recurring crystalline clay minerals, including kaolinite, illite, smectite, and montmorillonite. The presence of calcium oxide (CaO) in the calcite and portlandite minerals of CSA and lime augmented the strength potential of the soil-stabilizing system (SFSS).…”

“…The optimum silica fume content (OSFC) at 6% of utilization was determined based on the procedure arrogated by past researchers 9 , 18 , 19 , 22 . According to the literature, lime content adopted was selected as 3%, 6%, and 9% 18 , 26 , 40 . The CSA content was fixed similarly to the lime to maintain uniformity in investigating and comparing the effectiveness of CSA and lime on the silica fume-stabilized soil (SFSS).…”