THE EFFECTIVENESS OF SUPPLEMENTARY CEMENTING MATERIALS IN SUPPRESSING EXPANSION DUE TO ASR - ANOTHER LOOK AT THE REACTION-MECHANISMS .1. CONCRETE EXPANSION AND PORTLANDITE DEPLETION

Portlandite content (TGA) of cement pastes made with two condensed silica fumes, three pulverized fly ashes and one ground granulated blast furnace slag was measured up during a 1 year time period. Results were compared to expansions obtained for a 2 year time period in the CAN/CSA A23.2-14A Concrete Prism Method for concrete specimens made with two very alkali-silica reactive aggregates and tested at the same conditions and water/cement/SCM. No correlation was obtained between reduction in concrete expansion and the portlandite depletion which appears to be only a consequence of pozzolanic reaction.