Incorporation of a nanotechnology-based product in cementitious binders for sustainable mitigation of sulphate-induced heaving of stabilised soils

Eyo, Eyo; Abbey, Samuel J.; Ngambi, Samson; Ganjian, Eshmaiel; Coakley, Eoin

doi:10.1016/j.jestch.2020.09.002

Cited by 18 publications

(18 citation statements)

References 41 publications

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“…The highly alkaline environment of the pore fluid influences the dissolution of siliceous and aluminous compounds within the lattices of the clay minerals, which then reacts with Ca 2+ ions in the pore fluid to produce some cementitious products such as calcium-silicate-hydrate (C-S-H), calcium-aluminate-hydrate (C-A-H) and calcium-aluminate-silicate-hydrate (C-A-S-H). The long-term duration of these pozzolanic reactions within a highly alkaline environment promotes the formation of C-S-H and C-A-H, which bind the soil particles together, causing a long-term increase in the strength and stiffness of the treated soil [39][40][41][42][43][44][45][46][47][48].…”

Section: Introductionmentioning

confidence: 99%

Appropriate Use of Lime in the Study of the Physicochemical Behaviour of Stabilised Lateritic Soil under Continuous Water Ingress

et al. 2020

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Lime stabilisation is one of the traditional methods of improving the engineering properties of lateritic soils for use as subgrade and foundation materials for the construction of road pavements and highway embankments. Understanding the mechanical performance of lime-stabilised lateritic subgrades in terms of their durability under continuous water ingress will improve environmental sustainability by conserving scarce natural resources and reducing the environmental impacts of repair and replacement of pavements. However, there are several conflicting reports on the durability of lime-stabilised soils subjected to continuous water ingress and harsh environmental conditions. Therefore, this paper evaluates the influence of leaching on the physicochemical behaviour and durability of lime-stabilised lateritic soil under continuous water ingress, simulating the typical experience in a tropical environment. Variations in the strength and durability of the lateritic soil at various lime contents (0, 2.5, 5, 7.5, 10, 15, and 20 wt.%) and soaking periods (3, 7, 14 and 28 days) were evaluated by performing the California bearing ratio tests before and after subjecting the lime-lateritic soil (LLS) samples to continuous leaching using two modified leaching cells. Furthermore, physicochemical analysis was performed to assess the variation of cation concentrations and changes in the physical properties of the pore fluid as the leaching time progressed from 3 to 28 days. The results show that the minimum strength reduction index of the soil corresponds to its lime stabilisation optimum (LSO). Electrical conductivity decreased monotonically and almost uniformly with an increase in leaching time, irrespective of lime content. So, too, was calcium concentration and to a lesser degree for pH and potassium concentration. Adverse changes in the physicochemical behaviour of the LLS samples occurred at lime contents below and slightly above the optimum lime content of the soil. Whereas permanent pozzolanic reactions occurred at lime contents above the LSO and thus resulted in a 45-fold increase in strength and durability. The results are significant for reducing the detrimental effect of the leaching-induced deterioration of flexible pavements founded on tropical floodplains.

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Section: Introductionmentioning

confidence: 99%

Appropriate Use of Lime in the Study of the Physicochemical Behaviour of Stabilised Lateritic Soil under Continuous Water Ingress

et al. 2020

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“…Kaolin clay was supplied by KAOLIN (Malaysia) SDN BHD under the brand name MK40 as a white, finely ground, odorless powder. Kaolin clay was used because (i) it is a major component of minerals found in natural clay; (ii) it exhibits a uniform and consistent mineralogy; (iii) it has a low cation exchange capacity [ 5 , 40 ]; (iv) it has a higher alumina content than most other costly minerals and can thus release more alumina when the pH is high, thereby participating in the formation of ettringite which increases susceptibility to sulphate attack [ 10 , 28 ]. For these reasons, kaolin clay is a suitable control soil in the soil stabilization process.…”

Section: Methodsmentioning

confidence: 99%

“…The GGBS used in this study was collected from MDC Sungai Pentani Company, Malaysia. It was chosen to reduce the rate of ettringite formation through the provision of more Al and Si, which react with Ca 2+ to form complex cementing gels [ 10 , 35 , 36 ]. The denser structure and lower calcium ion content of GGBS should contribute to superior sulphate resistance [ 8 , 28 , 45 ].…”

Section: Methodsmentioning

confidence: 99%

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Novel Approach to the Treatment of Gypseous Soil-Induced Ettringite Using Blends of Non-Calcium-Based Stabilizer, Ground Granulated Blast-Furnace Slag, and Metakaolin

2021

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Gypseous soil is one type of expansive soil that contains a sufficient amount of sulphate. Cement and lime are the most common methods of stabilizing expansive soil, but the problem is that lime-treated gypseous soil normally fails in terms of durability due to the formation of ettringite, a highly deleterious compound. Moisture ingress causes a significant swelling of ettringite crystals, thereby causing considerable damage to structures and pavements. This study investigated the suitability of various materials (nano–Mg oxide (M), metakaolin (MK), and ground granulated blast-furnace slag (GGBS)) for the stabilization of gypseous soil. The results showed soil samples treated with 20% M-MK, M-GGBS, and M-GGBS-MK to exhibit lower swelling rates (<0.01% change in volume) compared to those treated with 10% and 20% of lime after 90 days of curing. However, soil samples stabilized with 10% and 20% binder of [(M-MK), (M-GGBS), and (M-GGBS-MK)] exhibited higher strengths after 90 days of soaking (ranging from 0.96–12.8 MPa) compared to those stabilized with 10% and 20% lime. From the morphology studies, the SEM and EDX analysis evidenced no formation of ettringite in the samples stabilized with M-MK-, M-GGBS-, and M-GGBS-MK. These results demonstrate the suitability of M-MK, M-GGBS, and M-GGBS-MK as effective agents for the stabilization of gypseous soil.

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“…Since natural sodium bentonite deposits are rarely found in abundance in some parts of the globe, clays containing kaolinite mineral (chemically weathered feldspar) of relatively lower swelling capacity are also sometimes used as sealants to contain wastes. Still, a mixture of bentonite with kaolinite and or without sand in different proportions have been used in the past as a probable compromise to satisfy cost and performance [3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Physical-Mechanical Characteristics of Treated Kaolin-Bentonite Mixture for Application in Compacted Liner Systems

et al. 2021

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Treated bentonite-rich soils used as liner materials in landfills may provide an effective solution to the problems of increased void ratios upon swelling at reduced suction as well as desiccation cracking when suction is increased during desaturation. Accordingly, this study provides an understanding of the evolution of void ratio of the mixed materials during swelling at three different suction levels upon saturation as well as the soil water retention (SWR) during desaturation. For the treatment process, low quantity of cement binder whose production leverages raw material resources with efficient dry-process kilns and the benefit of lower energy consumption were used. Results indicated increased mixed soils’ strength irrespective of increased fines content due to thixotropy. The mixed soils exhibited almost equal values of void ratios at different hydration stages, suggesting that slightly reduced expansion mostly affects the subsequent phases of moisture ingress at full saturation compared to the natural soils. Lower values of void ratio obtained at full saturation also suggests possible reduced infiltration of water into landfills. The observed increased moisture retention within the osmotic suction zone and a decrease in the same as the fines content increased in the mixed soils can aid contaminant encapsulation while also reducing desiccation cracking. The findings of this research are intended to serve as a benchmark for further studies using other sustainable materials for treatment of mixed soils.

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Incorporation of a nanotechnology-based product in cementitious binders for sustainable mitigation of sulphate-induced heaving of stabilised soils

Cited by 18 publications

References 41 publications

Appropriate Use of Lime in the Study of the Physicochemical Behaviour of Stabilised Lateritic Soil under Continuous Water Ingress

Appropriate Use of Lime in the Study of the Physicochemical Behaviour of Stabilised Lateritic Soil under Continuous Water Ingress

Novel Approach to the Treatment of Gypseous Soil-Induced Ettringite Using Blends of Non-Calcium-Based Stabilizer, Ground Granulated Blast-Furnace Slag, and Metakaolin

Microstructure and Physical-Mechanical Characteristics of Treated Kaolin-Bentonite Mixture for Application in Compacted Liner Systems

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