THE HYDRAULICS OF CRUSHED SLAG FINES /IN FRENCH/

THE PURPOSES OF THE STUDY WAS TO DETERMINE WHETHER, IN MIXTURES OF CRUSHED SLAG AND GRANULATED SLAG WITH OR WITHOUT CATALYST, THE CRUSHED SLAG BEHAVES AS AN INERT AGGREGATE OR WHETHER IT GIVES RISE ITSELF TO SETTING REACTIONS. THE CRUSHED SLAGS STUDIED CAME FROM FOUR DIFFERENT PLANTS, AND WERE 0/1 TO 0/5 SANDS. SIMPLE COMPRESSIVE STRENGTHS, WITH OR WITHOUT CATALYST, RICH LIME OR SODA, WERE DETERMINED AFTER DURATIONS OF PRESERVATION RANGING FROM 7 DAYS TO ONE YEAR. TWO CRUSHED SLAGS SET WITHOUT CATALYST; THE SETTING WAS VERY SLOW (APPRECIABLE AFTER 90 DAYS) BUT MARKED (25 TO 35 BARS AFTER ONE YEAR). ALL THE CRUSHED SLAGS SET WITH CATALYST; THE SETTING WAS MORE RAPID AND THE STRENGTHS MARKEDLY GREATER THAN WITHOUT CATALYST. WITH SODA, INITIAL STRENGTHS WERE MUCH HIGHER THAN WITH LIME, BUT THE RELATIVE DIFFERENCE DECREASED CONSIDERABLY AFTER ONE YEAR. THE EFFICACITY OF THE SODA CATALYST WAS CONFIRMED ON A 0/40 CRUSHED SLAG. THE CRUSHED SLAGS DID NOT BEHAVE LIKE INERT SUBSTANCES. THIS PROPERTY IS ATTRIBUTED TO A POOR CRYSTALLIZATION OF THE SLAG FOLLOWING TOO RAPID COOLING, WHICH IS ALSO AN UNFAVORABLE FACTOR FOR THE MECHANICAL STRENGTH OF THE AGGREGATE. MOREOVER, IN ORDER TO MOBILIZE THIS ACTIVITY OF THE CRUSHED SLAG MORE DEPENDABLY, A CATALYST MUST BE USED. THIS PHENOMENON MAY EXPLAIN WHY, IN GRAVEL-SLAG MIXTURES IN WHICH THE AGGREGATE IS A CRUSHED SLAG, THERE IS NOT ALWAYS A GOOD CORRELATION BETWEEN THE STRENGTHS OBTAINED AND THE COEFFICIENT OF THE GRANULATED SLAG. /LCPC/A/RRL/