Utilization of polymer stabilization for improvement of clay microstructures

Azzam, Waseim

doi:10.1016/j.clay.2014.03.006

Cited by 30 publications

(11 citation statements)

References 14 publications

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“…Fissures resulting from shrinkage can lead to reduction of the shear strength [8−11]. Therefore, lime [12], cement [13], sand [14], polymer [15] or fiber [16,17] have been used by many researchers to treat red clay to reduce its shrinkage. An optimum ratio of clay to sand was proposed after considering both the shrinkage and compressive strength results [18].…”

Section: Introductionmentioning

confidence: 99%

Study of Mutual Improvement of Completed Weathered Phyllite and Red Clay Based on Neutralization Effects of Swelling and Shrinkage Deformation

Zhao¹,

Yang²,

Rao³

et al. 2022

Journal of Renewable Materials

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Completely weathered phyllite (CWP) soil is a kind of special soil with high swell potential, while red clay is a special soil with high shrinkage. This means that these two kinds of special soils are usually not suitable for direct use as subgrade fill. To reduce the swell index of the CWP soil and the shrinkage of red clay at the same time, it was proposed to blend the CWP soil with red clay to improve their basic characteristics. A series of swell index tests and dry-wet cycle tests of the blended soils have been carried out at varying blending ratios, compaction coefficients and moisture contents. The test results show that the free swell index of the blended soil decreases with the increase of red clay, moisture content and compaction coefficient, respectively. The fissure density of the blended soil first decreases and then increases with the blending ratio, with the lowest being zero when the blending ratio is ranging from 20% to 40%. Through particle microscopic analysis and elemental composition analysis, it is found that the neutralization effect, the dilution effect of swell minerals, and the partition effect of coarse particles play an important role in restraining expansion and shrinkage deformation of the blended soil. Based on the liquid limit requirement of Chinese Railway Design Code (TB 10001-2016), the optimal blending ratio of red clay has been proposed to be 50%. Compared with the CWP soil, the free load swell index of the blended soil is reduced by 45.0% and the fissure density is reduced by 99.3% compared with that of red clay. Therefore, it is feasible to improve the CWP soil by blending it with red clay at an optimal ratio of 50% by using the neutralization effect of the expansion of CWP and shrinkage of red clay.

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Section: Introductionmentioning

confidence: 99%

Study of Mutual Improvement of Completed Weathered Phyllite and Red Clay Based on Neutralization Effects of Swelling and Shrinkage Deformation

Zhao¹,

Yang²,

Rao³

et al. 2022

Journal of Renewable Materials

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“…Other studies have tested the use of additives including waste materials such as lime and rice husk ashes to improve the geotechnical properties of an expansive clay soil subject to freeze-thaw effect, finding that the effects on soil behavior were positive [11]. Using polymer stabilization to create a new nanocomposite material with clay soil has been found to effectively stabilize slopes and road embankments [12,13]. Delinière et al [14] deal with the characterization of five ready-mixed clay plasters from French brickworks using the recent German standard.…”

Section: Introductionmentioning

confidence: 99%

Study of the Mechanical and Microscopic Properties of Modified Silty Clay under Freeze-Thaw Cycles

et al. 2022

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Silty clay can be found in the alpine region of the Qinghai province, China, where it is subject to annual freeze-thaw cycles. To investigate the static mechanical properties of silty clay modified by basalt fiber and basalt powder under the action of freeze-thaw cycles, triaxial compression tests and scanning electron microscope tests were conducted on the soil. The test results revealed that varying the number of freeze-thaw cycles resulted to different effects on the soil mechanical strength, which tended to increase after 2 cycles, but then tended to decline when subjected to 5–10 cycles. After 20 freeze-thaw cycles, soil strength reached a dynamic equilibrium state. The shear strength of basalt fiber soil and basalt powder soil increased by 7.55% and 5.12%, respectively, compared with that of normal soil under 30 freeze-thaw cycles. Subsequently increasing of the number of freeze-thaw cycles differentially affected the cohesion and internal friction angle of normal soil and admixture soils, and these soils gradually tended to stabilize at a mechanical strength higher than the initial value. Basalt fibers reinforced the soil to a higher degree than basalt powder at a dosage of 0.4% based on dry soil mass. The stress-strain curves of the three soil types can be simulated using the hyperbolic model. The results of the study can provide some theoretical reference for practical engineering in seasonal frozen soil areas.

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“…In this study, nuclear magnetic resonance (NMR) was used to quantitatively study the effects of the soil improvers on soil pore size distribution. In contrast to scanning electron microscopy (SEM) (Azzam, 2014; K. Li et al, 2020; Marto et al, 2014), NMR has the capability to detect the soil pore structure efficiently and non‐destructively (Yao et al, 2010). Based on the Young‐Laplace theory, the soil‐water characteristic curve (SWCC) can also be obtained using the relaxation time curve (Chen et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

New polymer composites improve silty clay soil microstructure: an evaluation using NMR

Huang

Sun

et al. 2021

Land Degrad Dev

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Soil erosion is a major environmental threat. The purpose of this study was to develop new polymer soil improvers that could mitigate the risk of soil erosion by modifying the microstructure of the soil and improving the ecological self‐repair ability. In particular, this study investigated new polymer composites (ADNB) based on different combination ratios of nano‐aqueous adhesive (NAB) and superabsorbent resin (SARn). The effects of different types of ADNB on soil water characteristics and pore size distribution were systematically investigated using nuclear magnetic resonance (NMR). In addition, an empirical model based on experimental data was developed to describe the effects of ADNB on the soil‐water characteristic curves. The results showed that in comparison to natural soil, the application of ADNB could significantly increase the peak signal strength of the relaxation time curve. In addition, ADNB can effectively reduce the number of pores with diameters of 1.11–8.3 μm, increase the number of pores with diameters of 0.5–1.8 μm, but had little effect on the number of pores with diameters of 0–0.5 μm. Through NMR imaging analysis, the effects of ADNB on soil moisture absorption and storage were quantified. The results showed that the ratio and content of ADNB have an obvious effect on the soil‐water characteristic curve under low suction but showed little effect under high suction conditions, indicating that the water‐holding capacity has been improved.

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Utilization of polymer stabilization for improvement of clay microstructures

Cited by 30 publications

References 14 publications

Study of Mutual Improvement of Completed Weathered Phyllite and Red Clay Based on Neutralization Effects of Swelling and Shrinkage Deformation

Study of Mutual Improvement of Completed Weathered Phyllite and Red Clay Based on Neutralization Effects of Swelling and Shrinkage Deformation

Study of the Mechanical and Microscopic Properties of Modified Silty Clay under Freeze-Thaw Cycles

New polymer composites improve silty clay soil microstructure: an evaluation using NMR

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