André Lecomte

Valorisation des LAC dans les mélanges granulaires: Partie 1: un modèle de dégradation

ABSTRACT This article in three parts deals with the degradation of Basic Oxygen Furnace Slag (BOF Slag) in wet media and associated expansion of granular mixtures containing these materials. The present text (part 1) proposes a model of degradation based on the quantification of the damages observed in the time by different BOF Slag placed in aqueous environment with various temperatures. It allows estimating a rate of degradation at a given age, either an age for which a rate of degradation will be reached, from the average content in free lime of the products and the surrounding temperature. The second article concerns the measurement of steam expansion realized on the same products, in the mould CBR adapted to the expansive test. The third part uses the results of the both previous models to consider the expansion of every granular mixture. This set can then serve to formulate granular mixtures of controlled expansion and help to the valorization of the BOF Slag in road.

Valorisation des LAC dans les mélanges granulaires: Partie 2: modélisation de la courbe d'expansion à la vapeur

ABSTRACT This article in three parts deals with the degradation of Basic Oxygen Furnace Slag (BOF Slag) in wet media and associated expansion of granular mixtures containing these materials. The part 1 proposed a model of degradation based on the quantification of the damages observed in time by different BOF Slag placed in aqueous media with various temperatures. The present article concerns the measurement of steam expansion realized on the same products, in the CBR mould adapted to the expansive test. The data allowed characterizing the obtained hyperbolic curve, according to the granular packing density and of a “free equivalent lime content” which depends on the age and on the size of grains. The third part uses the results of the both previous models to consider the expansion of every granular mixture. Then, this set can be used to formulate granular mixtures of controlled expansion and help to the valorization of the BOF Slag in road.

Valorisation des LAC dans les mélanges granulaires. Partie 3: modélisation de l’expansion d’un mélange quelconque

Cet article en trois parties s’intéresse à la dégradation des laitiers d’aciérie de conversion (LAC) en milieu humide et à l’expansion associée de mélanges granulaires contenant ces matériaux. La partie 1 propose un modèle de dégradation fondé sur la quantification des désordres observés dans le temps de plusieurs LAC placés en milieu aqueux à différentes températures. La partie 2 concerne les mesures d’expansion à la vapeur réalisées avec les mêmes produits, dans le moule CBR adapté à l’essai de gonflement. Les données ont permis de caractériser la courbe hyperbolique obtenue, en fonction de la compacité de l’empilement et d’une « teneur en chaux libre équivalente ». Le présent article utilise les résultats des deux modèles précédents pour estimer l’expansion d’un mélange granulaire quelconque. Cet ensemble peut servir ainsi à valoriser les LAC dans les mélanges granulaires d’expansion contrôlée destinés aux assises de chaussées. This article in three parts deals with the degradation of Basic Oxygen Furnace Slag (BOF Slag) in wet media and associated expansion of granular mixtures containing these materials. The part 1 proposed a model of degradation based on the quantification of the damages observed in time by different BOF Slag placed in aqueous media with various temperatures. The part 2 concerned the measurement of steam expansion realized on the same products, in the CBR mould adapted to the expansive test. The data allowed characterizing the obtained hyperbolic curve, according to the granular packing density and of a “free equivalent lime content”. The present article uses the results of the both previous models to consider the expansion of every granular mixture. Then, this set can be used to formulate granular mixtures of controlled expansion and help to the valorization of the BOF Slag in road.