The effects of carbonation and drying during intermittent leaching on the release of inorganic constituents from a cement-based matrix

Gervais, Caroline; Garrabrants, Andrew C.; Sanchez, Florence; Barna, Radu; Morand, Pierre; Kosson, David S.

doi:10.1016/s0008-8846(03)00248-5

Cited by 72 publications

(40 citation statements)

References 44 publications

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“…e carbonation reaction is supported by calcium hydroxide that is generated by the decalcification of CSH gel after the original level of portlandite formed during depletion of ordinary Portland cement (OPC) hydration [57]:…”

Section: Characterization Of the Materialsmentioning

confidence: 99%

Evaluation of Carbonation Effects on Cement‐Solidified Contaminated Soil Used in Road Subgrade

Zhou

Pan

Tang

et al. 2018

Advances in Materials Science and Engineering

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Cement solidification/stabilization is widely used towards contaminated soil since it has a low price and significant improvement for the structural capacity of soil. To increase the usage of the solidified matrix, cement-solidified contaminated soil was used as road subgrade material. In this study, carbonation effect that reflected the durability on strength characteristics of cementsolidified contaminated soil and the settlement of pavement were evaluated through experimental and numerical analysis, respectively. According to results, compressive strengths of specimens with 1% Pb(II) under carbonation and standard curing range from 0.44 MPa to 1.17 MPa and 0.14 MPa to 2.67 MPa, respectively. e relatively low strengths were attributed to immobilization of heavy metal, which consumed part of SiO 2 , Al 2 O 3 , and CaO components in the cement or kaolin and reduced the hydration and pozzolanic reaction materials. is phenomenon further decreased the strength of solidified soils. e carbonation depth of 1% Cu(II) or Zn(II) contaminated soils was 18 mm, which significantly increased with the increase of curing time and contamination concentration. Furthermore, the finite element calculation results showed that surface settlements decreased with the increase of modulus of subgrade and the distance away from the center. At the center, the pavement settlement was proportional to the level of traffic load.

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Section: Characterization Of the Materialsmentioning

confidence: 99%

Evaluation of Carbonation Effects on Cement‐Solidified Contaminated Soil Used in Road Subgrade

Zhou

Pan

Tang

et al. 2018

Advances in Materials Science and Engineering

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“…4). This process is a liquid-phase reaction of carbon dioxide with aqueous hydroxide and cations to produce carbonates [11]. The formation of other carbonate phases is also possible.…”

Section: Hydration and Carbonationmentioning

confidence: 99%

“…In a manner similar to Portland cement, the ash material undergoes chemical changes during the course of time and "ages". The carbonation of cement matrices has a significant physical effect on the mass transport properties of these materials through a narrowing of the pore structure due to the increase in solid volume (11%-12%) expected when portlandite is converted to calcium carbonate [11]. The carbonation of cement and concrete is not desirable because it causes a cracking of the structures and a reduction in strength.…”

Section: Hydration and Carbonationmentioning

confidence: 99%

“…The CO 2 source used can be either pure CO 2 gas or any other CO 2 -rich gas, such as the flue gas from incineration [16]. The approximate concentration of CO 2 in air is 0.035%, and the carbonation depth of structural concretes occurs at the rate of 1 cm per year [11]. It has been shown that the carbonation of cementitious materials, such as MSWI fly ash, occurs in minutes when exposed to high concentrations of CO 2 [16].…”

Section: Accelerated Carbonationmentioning

confidence: 99%

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Reactivity and Leaching of Wood Ash Pellets Dehydrated by Hot Air and Flue Gas

Sarenbo¹,

Mellbo²,

Stålnacke³

et al. 2009

TOWMJ

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Abstract:Companies that generate a large amount of wood ash will need an industrial process to agglomerate the ash and lower its reactivity, because untreated ash is a dust hazard for workers and is difficult to spread evenly on forest soil. In addition, untreated ash can cause burning damage to vegetation owing to its alkalinity and rapid release of salts. Production of large amounts of wood ash agglomerates demands an effective dehydration process. The reactivity and release of inorganic constituents from wood ash pellets dehydrated at room temperature using hot air and flue gas was investigated. Our results imply that flue gas-treated pellets have significantly lower reactivity in terms of pH and electrical conductivity, and release less Ca 2+ and more Mg 2+ compared to pellets dried at room temperature or in hot air. Ash pellets dehydrated in hot air are very reactive, and release more Ca 2+ than pellets dried in other ways. The formation of syngenite during the flue-gas treatment decreases K + release from the ash pellets.

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“…The results of recent investigations conducted under arid and semi-arid conditions (Al-Khayat et al 2002;Garrabrants et al 2002Garrabrants et al , 2003Garrabrants et al , and 2004Gervais et al 2004;Sanchez et al , 2003 provide valuable information suggesting structural and chemical changes to concrete waste forms which may affect contaminant containment and waste form performance. However, continued research is necessitated by the need to understand the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties, and the associated impact on contaminant release.…”

Section: Introductionmentioning

confidence: 99%