A review of the mechanical and leaching performance of stabilized/solidified contaminated soils

Kogbara, Reginald B.

doi:10.1139/er-2013-0004

Cited by 89 publications

(26 citation statements)

References 59 publications

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“…However, among the samples with total binder additions of 2.5%, cement-treated lead-contaminated soil (C2.5Pb1) had the highest value of UCS, 886.388 kPa, an increase of 124%; the UCS of lead-contaminated soil after 2.5% quicklime treatment (S2.5Pb1) reached 619.055 kPa, an improvement of 55.4%, while the UCS of lead-contaminated soil (F2.5Pb1) with 2.5% fly ash reached 499.331 kPa, an increase of only 25.3%. This indicates that the addition of cement, quicklime, and fly ash all improve the UCS of lead-contaminated soil, in agreement with Kogbara [47] and Du et al [26]. This occurs because, when cement is added to water, the main minerals in the cement, such as C 3 S (3CaO·SiO 2 ), C 2 S (2CaO·SiO 2 ), and C 3 A (3CaO·Al 2 O 3 ), undergo a hydration reaction (as shown in Table 6), generating calcium silicate hydrate gel (C-S-H) and calcium aluminate hydrate(C-A-H), which in turn fill and close the pores of specimens and encapsulate soil particles [29,47,50].…”

Section: Influence Of Freeze-thaw Cycles and Binder Dosage On Ucssupporting

confidence: 81%

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Influence of Freeze–Thaw Cycles and Binder Dosage on the Engineering Properties of Compound Solidified/Stabilized Lead-Contaminated Soils

Zhong

Wang

et al. 2020

IJERPH

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The solidification/stabilization (S/S) method is the usual technique for the remediation of soils polluted by heavy metal in recent years. However, freeze-thaw cycles, an important physical process producing weathering of materials, will affect the long-term stability of engineering characteristics in solidified contaminated soil. In addition, it is still questionable whether using large dosages of binders can enhance the engineering properties of solidified/stabilized contaminated soils. In this study, the three most commonly used binders (i.e., cement, quicklime, and fly ash), alone and mixed in different ratios, were thus added to lead-contaminated soil in various dosages, making a series of cured lead-contaminated soils with different dosages of binders. Afterward, unconfined compression strength tests, direct shear tests, and permeability tests were employed on the resulting samples to find the unconfined compressive strength (UCS), secant modulus (E 50 ), internal friction angle (ϕ), cohesion (c), and permeability coefficient (k) of each solidified/stabilized lead-contaminated soil after 0, 3, 7, and 14 days of freeze-thaw cycles. This procedure was aimed at evaluating the influence of freeze-thaw cycle and binder dosage on engineering properties of solidified/stabilized lead-contaminated soils. Results of our experiments showed that cement/quicklime/fly ash could remediate lead-contaminated soils. However, it did not mean that the more the dosage of binder, the better the curing effect. There was a critical dosage. Excessive cementation of contaminated soils caused by too much binder would result in loss of strength and an increase in permeability. Furthermore, it was found that UCS, E 50 , ϕ, c, and k values generally decreased with the increase in freeze-thaw cycle time-a deterioration effect on the engineering characteristics of solidified lead-contaminated soils. Avoiding excessive cementation, 2.5% cement or quicklime was favorable for the value of E 50 while a 2.5% fly ash additive was beneficial for the k value. It is also suggested that if the freeze-thaw cycle continues beyond the period supported by excessive cementation, such a cycle will rapidly destroy the original structure of the soil and create large cracks, leading to an increase in permeability. The results also showed that the contaminated soils with a larger dosage of binders exhibited more significant deterioration during freeze-thaw cycles.

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Section: Influence Of Freeze-thaw Cycles and Binder Dosage On Ucssupporting

confidence: 81%

“…For the sake of achieving optimal moisture content (OMC), as shown in Table 1, a certain amount of deionized water was added into the soil specimens. Under this OMC, UCS, and other mechanical properties of the soils were at their best conditions [47].…”

Section: Specimen Preparationmentioning

confidence: 79%

Influence of Freeze–Thaw Cycles and Binder Dosage on the Engineering Properties of Compound Solidified/Stabilized Lead-Contaminated Soils

Zhong

Wang

et al. 2020

IJERPH

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“…Stabilization results from the hydration reactions in the product and durability of the stabilized material is a key variable (Kogbara, 2014). UCS tests were performed on the prepared samples according to the ASTM D1633-07 standard.…”

Section: Methodsmentioning

confidence: 99%

Stabilization and Solidification of a Clay Soil Contaminated with MTBE

2017

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Stabilization and solidification a clay soil contaminated with MTBE Abstract:This paper presents an investigation into stabilization and solidification of a clay soil contaminated with MTBE (Methyl Butyl Ether) using two different agents (cement and mixture of bentonite and cement) through a program of laboratory experiments. The samples were prepared in two stages. In the first stage they were prepared with 20 and 30% cement but in the second stage they were prepared with 20 and 30% mixtures of bentonite and cement (with ratios of bentonite to cement equal to 1:1 and 3:1).Unconfined compression tests (UCT) and leaching tests using GC (Gas Chromatography) apparatus were conducted on the samples that were prepared in the above two stages at different curing times. The results show that by using cement, the strength of the soil is increased. The results of the leaching tests on contaminated soil show a major reduction in the concentration of MTBE. Adding cement to contaminated soil causes reduction in concentration of MTBE but by increasing the curing time the concentration of MTBE is increased. It is also indicted that using combination of bentonite and cement leads to reduction in MTBE concentration and the amount of reduction is decreased by increasing the curing time. The bentonite-cement ratio of 3:1 is more effective than 1:1 in reducing the concentration of MTBE.

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“…Kogbara [20] reviewed that the OPC dosage for contaminated soil may range from 4 to 20% by weight of dry mass. On basis of that the mixing proportion of cement and cement-bottom ash mix with dredged soil is taken as 4-20% by weight of the dry soil.…”

Section: Testing Proceduresmentioning

confidence: 99%

Contaminated dredged soil stabilization using cement and bottom ash for use as highway subgrade fill

2017

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IntroductionThe River Yamuna is a most important river of Delhi, capital of India and stretched within the zone of 22 km from Wazirabad to Okhala. Within this stretch 22 major drains of the capital, Delhi is connected and continuously discharging highly contaminated sediments, sewage and sludge effluents directly into it resulting in the rise of its bed level due to siltation day by day [5]. Thus, before monsoon every year dredging of the soils from each drain becomes essential. As recorded during 2010-2013 the total quantity of dredged soils removed from all the drains is approximately 8, 30,000 m 3 and in 2016 the quantity of dredged soil removed is about 3, 38,132 m 3 [17]. Due to scarcity of open land, the Government of Delhi is facing great problems to dispose these high quantities of dredged soils every year. The earlier practice of dumping of dredged soils into landfill areas or into open places caused a lot of environmental problems and suffering to local public which forced management authority for alternative solutions of its disposal. Currently, stabilization and solidification (S/S) processes have been recognized AbstractLarge amount of sediments are dredged from connecting drains of River Yamuna as a part of its regular maintenance in Delhi. These dredged soils generally considered as waste due to its poor engineering properties. In this study attempt has been made to improve strength, durability and immobilize contaminants of the contaminated dredged soil collected from Najafgarh drain by mixing it with different proportion of cement-bottom ash mix so that it can suitably fulfill the requirements of highway subgrade materials. Compaction test, California bearing ratio test, wetting and drying test, toxicity characteristic leaching procedure leachate test and scanning electron microscope test were performed on the contaminated dredged soil specimens and the results indicated that cement-bottom ash mix was effective in improving the engineering properties of the contaminated dredged soils. Also, the test results of the contaminated dredged soil stabilized with cement-bottom ash mix were better in comparison to cement alone. From the study it reveals that the optimum proportion of additive to be used to improve properties of the contaminated dredged soils was 10% cement + 10% bottom ash mix for use it as a highway subgrade fill materials. Gupta et al. Geo-Engineering (2017) Page 2 of 13 Gupta et al. Geo-Engineering (2017) 8:20 to treat such type of contaminated dredged soils containing heavy metals and to use it as valuable resources. Wilk et al. [28] reported the stabilization and reuse of contaminated dredged material from Former Wood Treating Facility, Port Newark, New Jersey and New York harbour dredged sediments using cement. He found that dredged material from Port Newark when treated with 8% cement achieved unconfined compressive strength greater than 1.7 MPa which was suitable for its use as base material for pavement whereas the dredged soil from New York harbour site got stabilized to...

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A review of the mechanical and leaching performance of stabilized/solidified contaminated soils

Cited by 89 publications

References 59 publications

Influence of Freeze–Thaw Cycles and Binder Dosage on the Engineering Properties of Compound Solidified/Stabilized Lead-Contaminated Soils

Influence of Freeze–Thaw Cycles and Binder Dosage on the Engineering Properties of Compound Solidified/Stabilized Lead-Contaminated Soils

Stabilization and Solidification of a Clay Soil Contaminated with MTBE

Contaminated dredged soil stabilization using cement and bottom ash for use as highway subgrade fill

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