Essai d’adsorption de bleu de méthylène : influence de paramètres du protocole expérimental sur la valeur au bleu en fonction de la minéralogie des argiles

Abstract

NDLR : Les discussions sur | cet article sont acceptées jusqu'au 30 avril 2008.The influence of the experimental protocol parameters of the methylene blue method on the determination of the blue value was studied on two argillaceous formations from the Parisian Region. Comparisons are made with three distinct types of clays. The results of this study reveal the importance of the protocol and the mineralogical composition of the material: -the methylene blue value of the argillaceous materials increases with the dispersion time and is stabilized in after about 24 h 83 83 Abstract -drying by freeze-drying allows a better access to surfaces of clay minerals, by comparison with drying with the drying oven; -the raw materials and the materials purified according to a precise protocol exhibit qualitatively the same behaviour, i. e., an increase in the methylene blue value with the dispersion time. However, for the same dispersion time methylene blue values are quantitativey higher for the purified clays than for the raw clays; -the heterogeneity of the layers inside the mixed-layered clay minerals influences the results: the presence of illite component in a mixed-layered illite /smectite clay mineral delays the accessibility to the swelling layers of smectite for a time lower than 24 h.

Formulation of Compressed Earth Blocks Stabilized by Glass Waste Activated with NaOH Solution

“…The precise surface was obtained by the following equation, which was consistent with that used in previous works like Laribi et al [45]:…”

Mécanismes de gonflement dans les sols fins ; application aux sols gonflants de la région parisienne

“…Finalement, quand tous les sites possibles d'adsorption sont saturés, l'eau (liquide) insérée dans le sol reste liquide, et la limite de liquidité est atteinte. On observe d'ailleurs une corrélation satisfaisante entre la limite de liquidité des sols et leur surface spécifique, en particulier déduite de la mesure de la valeur au bleu de méthylène (Tran, 1977 ;AFNOR, 1998 ;Laribi et al, 2007), qui est basée également sur la saturation de tous les sites d'adsorption par cette molécule en solution aqueuse.…”