Essai au bleu et nocivité des montmorillonites dans les matériaux composites

The behaviour in wet conditions of materials (aggregates, soils, rocks...) containing clay particles depends on both the latter content and its mineralogical nature. According to the technique involved (cement-treated soils, bituminous mixes, concrete...), only external surface area or both external and internal surface areas of the clays are dominantly relevant. In this paper, we describe two simple ways of using the Methylen Blue test which allow the swelling nature of the clays, through the ratio of the external to the internal surface areas as well as their amount to assessed for The operating procedures are given; potential applications are also discussed.