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Chemo-mechanical effects in kaolinite. Part 1, Prepared samples / A. S. Wahid in Géotechnique, Vol. 61 N° 6 (Juin 2011) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 6 (Juin 2011) . - pp. 439–447 Titre : Chemo-mechanical effects in kaolinite. Part 1, Prepared samples Type de document : texte imprimé Auteurs : A. S. Wahid, Auteur ; A. Gajo, Auteur ; R. Di Maggio, Auteur Année de publication : 2011 Article en page(s) : pp. 439–447 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Clays  permeability  Consolidation  Laboratory  tests  Chemical  properties  Shear  strength  Compressibility Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : The results of laboratory tests on chemo-mechanical interactions in kaolinite samples prepared with inorganic, salt, acid and base solutions are presented. In particular, the effects of the different solutions on the liquid limit, one-dimensional compressibility, permeability and residual shear strength are considered. Kaolinite proves relatively insensitive to salt solutions, whereas variations in pore fluid pH cause large strength changes, associated with non-negligible changes in one-dimensional compressibility. The partly inconsistent effects induced by acids and bases on the residual shear strength and on the one-dimensional compressibility do not permit any easy interpretation of the experimental evidence. Mineral dissolution and the associated formation of new compounds are probably involved in the behaviour observed. These aspects will be investigated in part 2 of this paper. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.067 [article] Chemo-mechanical effects in kaolinite. Part 1, Prepared samples [texte imprimé] / A. S. Wahid, Auteur ; A. Gajo, Auteur ; R. Di Maggio, Auteur . - 2011 . - pp. 439–447. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 6 (Juin 2011) . - pp. 439–447 Mots-clés : Clays  permeability  Consolidation  Laboratory  tests  Chemical  properties  Shear  strength  Compressibility Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : The results of laboratory tests on chemo-mechanical interactions in kaolinite samples prepared with inorganic, salt, acid and base solutions are presented. In particular, the effects of the different solutions on the liquid limit, one-dimensional compressibility, permeability and residual shear strength are considered. Kaolinite proves relatively insensitive to salt solutions, whereas variations in pore fluid pH cause large strength changes, associated with non-negligible changes in one-dimensional compressibility. The partly inconsistent effects induced by acids and bases on the residual shear strength and on the one-dimensional compressibility do not permit any easy interpretation of the experimental evidence. Mineral dissolution and the associated formation of new compounds are probably involved in the behaviour observed. These aspects will be investigated in part 2 of this paper. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.067

Chemo-mechanical effects in kaolinite. Part 2, Exposed samples and chemical and phase analyses / A. S. Wahid in Géotechnique, Vol. 61 N° 6 (Juin 2011) 

Public ISBD [article]  in Géotechnique > Vol. 61 N° 6 (Juin 2011) . - pp. 449–457 Titre : Chemo-mechanical effects in kaolinite. Part 2, Exposed samples and chemical and phase analyses Type de document : texte imprimé Auteurs : A. S. Wahid, Auteur ; A. Gajo, Auteur ; R. Di Maggio, Auteur Année de publication : 2011 Article en page(s) : pp. 449–457 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Clays  Compressibility  Consolidation  Chemical  properties  Laboratory  tests Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Continuing from part 1 of this paper, the results of laboratory tests on chemo-mechanical interactions in kaolinite subjected to the diffusion of inorganic, salt, acid and base solutions under an applied stress state are presented. Chemical analyses on the surnatant and analyses on X-ray diffraction patterns, high-temperature differential scanning calorimetry thermal gravimetry scans and transmission electron microscopy micrographs led to the conclusion that the bulk of kaolinite mineral is probably only slightly affected by the chemical interactions, the chemical attack being concentrated mainly at the particle edges, where it induces a change in the shape of the edges, which become irregular and less sharp. The mechanical behaviour of kaolinite is not affected by pore fluid salinity, but it is significantly affected by pore fluid pH: both acid or base solutions under an applied stress cause significant volumetric compression. Such strains are irreversible and probably related to the particle rearrangement induced mainly by the degradation of the particle edges, in addition to the decrease in basal friction angle (described in the companion paper) and the change of strength at edge-to-face contact points. The mechanical effects are slightly related to the dielectric constant of the pore fluid and this is consistent with the general conviction that interactions between kaolinite particles are mostly mechanical. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.068 [article] Chemo-mechanical effects in kaolinite. Part 2, Exposed samples and chemical and phase analyses [texte imprimé] / A. S. Wahid, Auteur ; A. Gajo, Auteur ; R. Di Maggio, Auteur . - 2011 . - pp. 449–457. Génie Civil Langues : Anglais (eng) in Géotechnique > Vol. 61 N° 6 (Juin 2011) . - pp. 449–457 Mots-clés : Clays  Compressibility  Consolidation  Chemical  properties  Laboratory  tests Index. décimale : 624 Constructions du génie civil et du bâtiment. Infrastructures. Ouvrages en terres. Fondations. Tunnels. Ponts et charpentes Résumé : Continuing from part 1 of this paper, the results of laboratory tests on chemo-mechanical interactions in kaolinite subjected to the diffusion of inorganic, salt, acid and base solutions under an applied stress state are presented. Chemical analyses on the surnatant and analyses on X-ray diffraction patterns, high-temperature differential scanning calorimetry thermal gravimetry scans and transmission electron microscopy micrographs led to the conclusion that the bulk of kaolinite mineral is probably only slightly affected by the chemical interactions, the chemical attack being concentrated mainly at the particle edges, where it induces a change in the shape of the edges, which become irregular and less sharp. The mechanical behaviour of kaolinite is not affected by pore fluid salinity, but it is significantly affected by pore fluid pH: both acid or base solutions under an applied stress cause significant volumetric compression. Such strains are irreversible and probably related to the particle rearrangement induced mainly by the degradation of the particle edges, in addition to the decrease in basal friction angle (described in the companion paper) and the change of strength at edge-to-face contact points. The mechanical effects are slightly related to the dielectric constant of the pore fluid and this is consistent with the general conviction that interactions between kaolinite particles are mostly mechanical. DEWEY : 624.15 ISSN : 0016-8505 En ligne : http://www.icevirtuallibrary.com/content/article/10.1680/geot.8.p.068