Publications Scientifiques

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    Rheological behavior of cement-based grout with Algerian bentonite
    (Springer Nature, 2019) Benyounes, Khaled
    he rheological parameters, yield stress, flow index, consistency, and plastic viscosity of cement grouts are important parameters for the quality control of these materials. These parameters are assessed from the rheogram using a rheo-logical model. Cement slurries without additive indicated a non-Newtonian type of rheological behaviour with yield stress. On the other hand, the mixtures containing a viscosifying agent exhibit a shear-thinning rheological behaviour which is much more important than the mixtures without a viscosifying agent. In this work, we formulated non-hydrated Algerian bentonite cement slurry in the presence of a superplasticizer. Cement was replaced cement by bentonite in five different substitution rates (2%, 4%, 6%, 8%, and 10%) and the water/binder ratio was fixed at 0.5. For this, various rheological tests were realized by using a controlled stress rheometer. In order to show the influence of bentonite on the rheological behaviour of the different grouts, several flow tests were carried out for a range of shear rates between 0.01 and 200 s−1. To properly adjust the different rheograms, various rheological models were used such as the models of Bingham, Herschel–Bulkley, modified Bingham, Casson, De Kee, Vom Berg, Yahia and Papanastasiou. For the correct choice of the rheological model, it was based on the calculation of the standard error. It was found that the rheological models of Herschel–Bulkley and Papanastasiou made it possible to better describe the flow curves compared to the other rheological models. It has been found that as the content of bentonite increases, the yield stress and the consistency evolve drastically, by cons the flow index decreases progressively
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    The effect of carboxymethylcellulose and xanthan on the rheology of bentonite suspensions
    (Taylor & Francis, 2010) Benyounes, Khaled; Mellak, A.; Benchabane, A.
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    Caractérisation rhéologique de la bentonite de maghnia en suspension aqueuse sans et avec additifs anioniques
    (2010) Benyounes, Khaled; Benchabane, A.; Mellak, A.
    L'objectif de ce travail est l’étude de l'effet de l’ajout de deux polymères anioniques sur les caractéristiques rhéologiques d'une suspension aqueuse de bentonite algérienne de forage (de Maghnia, Ouest de l’Algérie). Les additifs sont la gomme de xanthane et le carboxymethylcellulose, CMC, utilisés souvent dans la formulation des boues de forage. Dans cet article, nous présentons et discutons des mesures rhéologiques réalisés sur : 1) une suspension aqueuse de bentonite (3%), 2) des polymères en solution aqueuse (le xanthane et le CMC à trois poids moléculaires différentes) et 3) des mélanges eau-bentonite-(xanthane ou CMC) à différentes concentrations de polymère. Ce travail a permis, notamment, de renforcer la conclusion rapportée dans des travaux conduits antérieurement sur la base d’une bentonite de laboratoire, montrant la dominance du comportement rhéologique du CMC et de xanthane sur celui de la suspension de bentonite