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Biologically inspired silicification process for improving mechanical properties of sand / Joseph E. Dove in Journal of geotechnical and geoenvironmental engineering, Vol. 137 N° 10 (Octobre 2011) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 10 (Octobre 2011) . - pp. 949-957 Titre : Biologically inspired silicification process for improving mechanical properties of sand Type de document : texte imprimé Auteurs : Joseph E. Dove, Auteur ; Craig M. Shillaber, Auteur ; Timothy S. Becker, Auteur Année de publication : 2012 Article en page(s) : pp. 949-957 Note générale : Géotechnique Langues : Anglais (eng) Mots-clés : Biologically-inspired  material  Ground  treatment  Silicification  Grout  Shear  strength  Compressive  strength Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A new type of ground treatment method is developed to improve the engineering properties of coarse-grained soils. By using biochemical concepts derived from recent discoveries into how organisms produce silicified skeletons, a silicification process is reported that offers environmental and physical advantages over some traditional methods by using nontoxic, commercially available components with a low potential for adverse environmental effects. Silicification begins by first pretreating the soil with a commercially available cationic polyelectrolyte, which is then followed by injecting a mixture of commercial sodium silicate and buffer. The silicification solutions have a pH of 5.0–5.5, weakly acidic values that are within the range of surface soil environments in temperate weathering regions. Gel time is regulated by the sodium silicate or polyelectrolyte concentration. The compressive strengths are measured as a function of polyelectrolyte type and concentration by using samples of Ottawa 20/30 sand silicified with a 20% sodium silicate by volume. Unconfined compressive strengths range from 150 to 198 kPa and are shown to be equal to or higher than soils treated at similar silicate concentrations with traditional and alternative formulations. Drained triaxial compression test results show that silicification improves strength and initial stiffness and increases the amount of volume change attributable to dilation. In principle, the methods developed in this paper for coarse-grained soils are also applicable to fractured rock and to fine-grained soils. Developing materials and processes for ground treatment by using inspiration from biological systems offers the promise of improved geomechanical performance, lower embodied energy, and lower cost than current treatment methods. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i10/p949_s1?isAuthorized=no [article] Biologically inspired silicification process for improving mechanical properties of sand [texte imprimé] / Joseph E. Dove, Auteur ; Craig M. Shillaber, Auteur ; Timothy S. Becker, Auteur . - 2012 . - pp. 949-957. Géotechnique Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 137 N° 10 (Octobre 2011) . - pp. 949-957 Mots-clés : Biologically-inspired  material  Ground  treatment  Silicification  Grout  Shear  strength  Compressive  strength Index. décimale : 624.1 Infrastructures.Ouvrages en terre. Fondations. Tunnels Résumé : A new type of ground treatment method is developed to improve the engineering properties of coarse-grained soils. By using biochemical concepts derived from recent discoveries into how organisms produce silicified skeletons, a silicification process is reported that offers environmental and physical advantages over some traditional methods by using nontoxic, commercially available components with a low potential for adverse environmental effects. Silicification begins by first pretreating the soil with a commercially available cationic polyelectrolyte, which is then followed by injecting a mixture of commercial sodium silicate and buffer. The silicification solutions have a pH of 5.0–5.5, weakly acidic values that are within the range of surface soil environments in temperate weathering regions. Gel time is regulated by the sodium silicate or polyelectrolyte concentration. The compressive strengths are measured as a function of polyelectrolyte type and concentration by using samples of Ottawa 20/30 sand silicified with a 20% sodium silicate by volume. Unconfined compressive strengths range from 150 to 198 kPa and are shown to be equal to or higher than soils treated at similar silicate concentrations with traditional and alternative formulations. Drained triaxial compression test results show that silicification improves strength and initial stiffness and increases the amount of volume change attributable to dilation. In principle, the methods developed in this paper for coarse-grained soils are also applicable to fractured rock and to fine-grained soils. Developing materials and processes for ground treatment by using inspiration from biological systems offers the promise of improved geomechanical performance, lower embodied energy, and lower cost than current treatment methods. DEWEY : 624.1 ISSN : 1090-0241 En ligne : http://ascelibrary.org/gto/resource/1/jggefk/v137/i10/p949_s1?isAuthorized=no