- Treffer 1 von 1
Swelling pressure of a divalent-rich bentonite: Diffuse double-layer theory revisited
- Physicochemical forces are responsible for the swelling pressure development in saturated bentonites. In this paper, the swelling pressures of several compacted bentonite specimens for a range of dry density of 1.10–1.73 Mg/m3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na+ ions. The theoretical swelling pressure–dry density relationshipPhysicochemical forces are responsible for the swelling pressure development in saturated bentonites. In this paper, the swelling pressures of several compacted bentonite specimens for a range of dry density of 1.10–1.73 Mg/m3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na+ ions. The theoretical swelling pressure–dry density relationship for the bentonite was determined from the Gouy-Chapman diffuse double-layer theory. A comparison of experimental and theoretical results showed that the experimental swelling pressures are either smaller or greater than their theoretical counterparts within different dry density ranges. It is shown that for dry density of the clay less than about 1.55 Mg/m3, a possible dissociation of ions from the surface of the clay platelets contributed to the diffuse double-layer repulsion. At higher dry densities, the adsorptive forces due to surface and ion hydration dominated the swelling pressures of the clay. A comparison of the modified diffuse double-layer theory equations proposed in the literature to determine the swelling pressures of compacted bentonites and the experimental results for the clay in this study showed that the agreement between the calculated and experimental swelling pressure results is very good for dry densities less than 1.55 Mg/m3, whereas at higher dry densities the use of the equations was found to be limited.…
Dokumentart: | Artikel (Wissenschaftlicher) |
---|---|
Verfasserangaben: | Tom Schanz, Snehasis Tripathy |
DOI (Zitierlink): | https://doi.org/10.1029/2007WR006495Zitierlink |
URN (Zitierlink): | https://nbn-resolving.org/urn:nbn:de:gbv:wim2-20170425-31592Zitierlink |
Titel des übergeordneten Werkes (Englisch): | Water Resources Research |
Sprache: | Englisch |
Datum der Veröffentlichung (online): | 25.04.2017 |
Jahr der Erstveröffentlichung: | 2009 |
Datum der Freischaltung: | 25.04.2017 |
Veröffentlichende Institution: | Bauhaus-Universität Weimar |
Institute und Partnereinrichtugen: | Fakultät Bauingenieurwesen / Professur Bodenmechanik |
Freies Schlagwort / Tag: | Geochemical modeling; Soils; High-pressure behavior; bentonite; clays; expansive clays |
GND-Schlagwort: | Bentonit; Boden; Ton |
DDC-Klassifikation: | 500 Naturwissenschaften und Mathematik / 530 Physik |
500 Naturwissenschaften und Mathematik / 540 Chemie | |
BKL-Klassifikation: | 35 Chemie / 35.24 Klassische analytische Chemie |
Lizenz (Deutsch): | Zweitveröffentlichung |