Journal of Sustainable Metallurgy

, Volume 4, Issue 3, pp 326–332 | Cite as

Modulation of Alpha Coefficient (α) and Reactivity in Granulated Blast Furnace Slag Binders Used in Road Construction

  • Cécile Diliberto
  • Lyès Chaouche
  • Romain Trauchessec
  • Samyr El Bedoui
  • André Lecomte
  • Patrice Reeb
  • Klaus-Jürgen Arlt
Research Article


Granulated or ground granulated blast furnace slags (GBFS and GGBFS, respectively) are common products used as hydraulic binders (sand 0/2) in road construction or after grinding as an addition to clinker or as an addition in concrete formulations. In road construction, the pavement structure layers are described by the EN 14227-2 standard. The reactivity of the GBFS is defined by the alpha coefficient (α) which is the product of the specific surface of the fines by the sand friability (EN 13286-44). The higher the α coefficient is, the better the reactivity of the slag. Based on the physico-chemical characterization of 28 samples of GBFS produced at the same plant, this study shows that the α coefficient is variable whereas the others characteristics such as chemical compositions or water content are constant. This variability is essentially due to the specific surface of fines, which represent only a very small fraction of GBFS. In order to control the mechanical performance of road granular mixtures, addition of different proportion (0, 1, 2.5 and 5 wt%) of GGBFS has been investigated for 1 year. This article shows that an addition of 2.5 or 5 wt% of GGBFS can be used to improve the mechanical performance of the hydraulic bound mixtures and modulate the α coefficient variations.


GBFS GGBFS Alpha coefficient Road granular mixtures 


Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© The Minerals, Metals & Materials Society 2018

Authors and Affiliations

  1. 1.Institut Jean Lamour, UMR/CNRS 7198, Université de Lorraine, Equipe “Matériaux pour le Génie Civil”, IUTNBVillers-les NancyFrance
  2. 2.Cerema, Direction territoriale Est, Laboratoire Régional de NancyTomblaineFrance
  3. 3.Aktien-Gesellschaft der Dillinger HüttenwerkeDillingen/SaarGermany

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