STRENGTH, PORE STRUCTURE AND PERMEABILITY OF ALKALI-ACTIVATED SLAG MORTARS

This paper deals with the strength development, pore structure develop ment, rapid chloride permeability and water permeability of alkali-act ivated slag mortars activated by 6% (by mass of Na2O) NaOH, Na2CO3 and Na2SiO3. The Na2SiO3-activated slag mortars exhibited the highest str ength at both early and later ages, even much higher than a typical co mmercial Type III portland cement. NaOH-activated slag mortars exhibit ed the lowest strength. The pore structure measurements were consisten t with strength results. Four common strength-porosity equations: Bals hin's, Ryshkevitch's, Schiller's, and Hasselmann's equations, fit the experimental results from alkali-activated slag mortars with sufficien t efficiency; of which Hasselmann's equation fit best. The charge pass ed through the mortar specimens in the rapid chloride ion permeability test appeared to be dependent more on the chemistry of pore solution than on the pore structure of the mortars. Limited results from water permeability testing appeared to be consistent with strength and pore structure measurements. Copyright (C) 1996 Elsevier Science Ltd