ADHESION AND POROSITY OF BLAST-FURNACE SLAG

ADHESIVITE ET POROSITE DU LAITIER DE HAUT-FOURNEAU.

THIS PAPER WAS PRESENTED AT A SEMINAR ON THE ADHESION OF ROAD AGGREGATES AT THE EXPOMAT 74 EXHIBITION, ON 15TH MAY 1974. BLAST FURNACE SLAG IS A COMPLEX MINERAL, THE COMPACTNESS OF WHICH AND RESULTING POROSITY ARE FUNCTIONS OF COOLING CONDITIONS. DEPENDING ON THE DIMENSIONS OF ITS VOIDS, THE SLAG IS DESCRIBED AS MICRO-POROUS (VOIDS SMALLER THAN 1 MM), CELLULAR (CAVITIES EXPRESSED IN CM) OR COMPACT (ABSENCE OF CAVITIES, BUT WITH ROUGH SURFACE TEXTURE). IN SURFACE DRESSING, THE RELATION BETWEEN POROSITY AND ACTIVE ADHESION (QUALITY OF THE LINKS BETWEEN MINERAL AND BINDER) IS FAVOURABLE. WITH A DRY SLAG OR A MODERATELY MOIST ONE (WATER CONTENT BELOW 1%) THE ADHESION OF THE BINDER IS GOOD, PARTICULARLY IN THE PRESENCE OF TAR PRODUCTS. THE PASSIVE ADHESION (RESISTANCE TO STRIPPING) IS GENERALLY EXCELLENT. IN THE CASE OF COMPACT CHIPPINGS, STRIPPING RESULTS IN THE BINDER STICKING TO THE SIDES OF THE AGGREGATE WHILE THE EDGES ARE UNCOVERED. WITH POROUS CHIPPINGS, THE BINDER TENDS TO FILL THE CAVITIES. BITUMINOUS MATERIALS WITH SLAG POSES THE PROBLEM OF THE PROPORTIONING OF THE BINDER, TAKING INTO ACCOUNT THE POROSITY OF THE MATERIAL. IT IS NECESSARY TO TAKE ACCOUNT OF THE INTER-GRANULAR VOIDS AND ACCESSIBLE VOIDS OF THE MACRO-POROUS TYPE WHICH WILL BE REVEALED BY AN EXCESS USE OF BINDER.

Language

  • French

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Filing Info

  • Accession Number: 01296730
  • Record Type: Publication
  • Source Agency: Institut Francais des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)
  • Files: ITRD
  • Created Date: Nov 21 2010 6:02AM