Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Swelling behavior of divalent and monovalent Indian bentonites in isochoric and free swelling conditions
https://orcid.org/0000-0003-3672-8936
Abstract The swelling pressure of the bentonite buffers plays an important role in the design of deep geological nuclear waste repositories. The present article highlighted the swelling behavior of Na-monovalent and Ca-Mg divalent Indian bentonites in isochoric (constant volume) and free swelling conditions. Constant volume swelling pressure tests and one-dimensional free swelling strain tests were conducted on the bentonites with an initial specimen dry density of 1.6 Mg/$ m^{3} $. The pore size distribution (PSD) and morphological changes of bentonites in free swelling and isochoric swelling conditions were examined through MIP and FESEM tests. The results showed that in the free swelling condition, the monovalent bentonite exhibited a higher swelling strain (126.2%) and a higher water absorption capacity (107%). On the other hand, the exerted swelling pressure and water absorption capacity of divalent bentonite (4.34 MPa, 36.1%) were found to be higher as compared to monovalent bentonite (1.42 MPa, 31.4%) in isochoric conditions. It indicates that the phenomenon of free swelling characteristics is different from the swelling pressure measured in isochoric conditions. The MIP and FESEM images showed that the hydration phenomenon caused a significant decrease and increase in macropores volume of bentonites in isochoric and free swelling conditions, respectively, especially for monovalent bentonite. However, micropore volume was noted to be increased and decreased marginally for isochoric and free swelling conditions, respectively. The free swelling phenomenon of the bentonites depends on the type of exchangeable cations and mineralogy. In isochoric conditions, along with cations and mineralogy, the swelling pressure depends on the PSD of bentonites.
Swelling behavior of divalent and monovalent Indian bentonites in isochoric and free swelling conditions
https://orcid.org/0000-0003-3672-8936
Abstract The swelling pressure of the bentonite buffers plays an important role in the design of deep geological nuclear waste repositories. The present article highlighted the swelling behavior of Na-monovalent and Ca-Mg divalent Indian bentonites in isochoric (constant volume) and free swelling conditions. Constant volume swelling pressure tests and one-dimensional free swelling strain tests were conducted on the bentonites with an initial specimen dry density of 1.6 Mg/$ m^{3} $. The pore size distribution (PSD) and morphological changes of bentonites in free swelling and isochoric swelling conditions were examined through MIP and FESEM tests. The results showed that in the free swelling condition, the monovalent bentonite exhibited a higher swelling strain (126.2%) and a higher water absorption capacity (107%). On the other hand, the exerted swelling pressure and water absorption capacity of divalent bentonite (4.34 MPa, 36.1%) were found to be higher as compared to monovalent bentonite (1.42 MPa, 31.4%) in isochoric conditions. It indicates that the phenomenon of free swelling characteristics is different from the swelling pressure measured in isochoric conditions. The MIP and FESEM images showed that the hydration phenomenon caused a significant decrease and increase in macropores volume of bentonites in isochoric and free swelling conditions, respectively, especially for monovalent bentonite. However, micropore volume was noted to be increased and decreased marginally for isochoric and free swelling conditions, respectively. The free swelling phenomenon of the bentonites depends on the type of exchangeable cations and mineralogy. In isochoric conditions, along with cations and mineralogy, the swelling pressure depends on the PSD of bentonites.
Swelling behavior of divalent and monovalent Indian bentonites in isochoric and free swelling conditions
https://orcid.org/0000-0003-3672-8936
Abstract The swelling pressure of the bentonite buffers plays an important role in the design of deep geological nuclear waste repositories. The present article highlighted the swelling behavior of Na-monovalent and Ca-Mg divalent Indian bentonites in isochoric (constant volume) and free swelling conditions. Constant volume swelling pressure tests and one-dimensional free swelling strain tests were conducted on the bentonites with an initial specimen dry density of 1.6 Mg/$ m^{3} $. The pore size distribution (PSD) and morphological changes of bentonites in free swelling and isochoric swelling conditions were examined through MIP and FESEM tests. The results showed that in the free swelling condition, the monovalent bentonite exhibited a higher swelling strain (126.2%) and a higher water absorption capacity (107%). On the other hand, the exerted swelling pressure and water absorption capacity of divalent bentonite (4.34 MPa, 36.1%) were found to be higher as compared to monovalent bentonite (1.42 MPa, 31.4%) in isochoric conditions. It indicates that the phenomenon of free swelling characteristics is different from the swelling pressure measured in isochoric conditions. The MIP and FESEM images showed that the hydration phenomenon caused a significant decrease and increase in macropores volume of bentonites in isochoric and free swelling conditions, respectively, especially for monovalent bentonite. However, micropore volume was noted to be increased and decreased marginally for isochoric and free swelling conditions, respectively. The free swelling phenomenon of the bentonites depends on the type of exchangeable cations and mineralogy. In isochoric conditions, along with cations and mineralogy, the swelling pressure depends on the PSD of bentonites.
Swelling behavior of divalent and monovalent Indian bentonites in isochoric and free swelling conditions
Jadda, Koteswaraarao (Autor:in) / Bag, Ramakrishna (Autor:in)
2023
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
BKL:
56.00$jBauwesen: Allgemeines
/
38.58
Geomechanik
/
38.58$jGeomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
56.00
Bauwesen: Allgemeines
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB18
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