FREEZE-THAW DURABILITY OF ACTIVATED BLAST-FURNACE SLAG CEMENT CONCRETE

The results of freeze-thaw testing (ASTM C 666) and the analysis of th e air-void parameters (ASTM C 457) of activated blast furnace slag cem ent (ABFSC) concrete mixes using sodium carbonate and sodium silicate activation are presented and discussed and compared with the results o btained from testing a conventional ordinary portland cement (OPC) con crete mix. The results from both normal moist-cured specimens and heat -cured specimens are presented. A full range of air content categories were examined. All concretes examined incorporated a water-to-binder (w/b) ratio of 0.44 and a binder content of 420 kg/m(3). Results demon strate that the AEA used was effective at entraining air with excellen t characteristics in the sodium silicate ABFSC concrete, but at dosage s much higher than required for OPC concrete. The durability of this c oncrete was high and similar to that of OPC concrete. The characterist ics of the air-void system in the sodium carbonate ABFSC concrete were poor and durability performance was generally low. The workability of all ABFSC mixes improved over the full range of air contents similar to OPC concrete. In all cases freeze-thaw performance, both with respe ct to durability factor and loss in mass due to specimen scaling, was observed to be generally dependent on air content and air bubble spaci ng factors.