Performance of the bentonite barrier at temperatures beyond 100°C: A critical review

Wersin, Paul; Johnson, L. H.; McKinley, Ian G.

doi:10.1016/j.pce.2006.02.051

Cited by 141 publications

(71 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Drief et al (2002) found that the transformation from smectite to illite also occurred when the sample was heated up to 50 0 C for 30 days in enriched sea water. Wersin et al (2006) indicated that the increase in temperature may cause the smectite mineral to become unstable and transform to more stable silicate plates in a process which is known as illiation.…”

Section: Discussionmentioning

confidence: 99%

Effect of thermal history on the properties of bentonite

Estabragh

Khosravi²

2016

Environ Earth Sci

View full text Add to dashboard Cite

The effect of thermal history on the properties of bentonite was studied through a number of experimental tests. The desired thermal history was created on samples of bentonite by keeping them at a fixed temperature (50, 100, 150, 200 and 250 o C) for a specific duration (3, 7, 14 and 30 days). Standard compaction, Atterberg limits, free swelling and swelling pressure tests were carried out on the samples on the dry side of optimum, optimum and wet side of optimum of the compaction curve with desired thermal history. In addition chemical tests were carried out on the flooding water at the end of the swelling test. The results showed that the changes in compaction characteristics were not considerable but the Atterberg limits, free swelling and swelling pressure of the soil were changed due to the thermal history in comparison with the soil without any thermal history. The magnitudes of free swelling and swelling pressure were dependent on the location of prepared sample on the compaction curve. In addition, the changes in Atteberg limits and swelling parameters (amount of free swelling and swelling pressure) were functions of magnitude of temperature and duration of time that the sample experienced the temperature in its temperature history. The effects of temperature and also duration of exposure of the soil to temperature was discussed with the aid of the Diffuse Double Layer (DDL) theory. It was found that the temperature may change the gradation of soil due to cementation of particles as a result of formation of some salts and oxides that help to paste the particles together and change the properties of the soil.

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of thermal history on the properties of bentonite

Estabragh

Khosravi²

2016

Environ Earth Sci

View full text Add to dashboard Cite

show abstract

“…Fairly extensive studies have been conducted to evaluate the occurrence of illitization in bentonite and clay formation; some of these studies are listed in Table 5-2 and a brief summary of each study is given below. Illitization is clearly evidenced in geological system (Wersin et al, 2007), as exemplified by several natural analogue studies (Pusch and Madsen, 1995;Kamei et al, 2004;Cuadros, 2006;Casciello et al, 2011). Illite/smectite mixed-layer clay is commonly observed in the clayey sediments, and typically the deep formation contains more illite than shallow formation (Cuadros, 2006), which lead to a conclusion that smectite is gradually transformed to illite during diagenesis.…”

Section: Detailed Mechanistic Modeling Of Thmc Alterationsmentioning

confidence: 97%

“…Higher temperature is certainly one of the factors that could increase the corrosion rate. A high temperature could also result in chemical alteration of buffer and backfill materials (bentonite) within the EBS through illitization and cementation, which compromise the function of these EBS components by reducing their plasticity and capability to swell when wetting (Pusch and Karnland, 1996;Pusch et al, 2010;Wersin, 2007). The swelling capability of clay is important for sealing gaps between bentonite blocks, among related EBS components, and between EBS and surrounding host rock.…”

Section: Introductionmentioning

confidence: 99%

“…For a tunnel located at 500 m depth, and assuming hydrostatic conditions, the pore pressure is around 50 bars. At this condition the boiling point is 264 o C rather than 100 o C. Wersin et al (2007), after reviewing a number of data sets, concluded that this criterion of 100 o C for the maximum temperature within the bentonite buffer is too conservative, based on their findings that no significant changes in bentonite properties occur at temperatures of at least 120 o C under wet conditions and bentonite is stable to even much higher temperature under dry conditions. Pusch (2000) and Pusch et al (2003) also found that the swelling pressure of compacted bentonite was not significantly affected by heating up to 125 o C.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Report on THMC Modeling of the Near Field Evolution of a Generic Clay Repository: Model Validation and Demonstration

Liu¹

2013

View full text Add to dashboard Cite

“…Reviews of the performance of bentonite backfill at temperatures exceeding 100 o C (e.g., Wersin et al, 2007;Pusch et al, 2010), modeling Zheng et al, 2014a), and experiment studies (e.g. Pusch et al, 2003;Caporuscio et al, 2012;Cheshire et al, 2013;Cheshire et al, 2014) of the mechanical and chemical changes at temperature up to 300 o C showed little or moderate deterioration of bentonite.…”

Section: Layout For 12 Pwr Waste Packagementioning

confidence: 99%