Reactivity of flash-calcined illitic clays

The paper discusses the reactivity of flash-calcined illitic clays for application as an alternative source of supplementary cementitious material. Structural and morphological changes induced by flash calcination improved the illitic clay reactivity despite the incomplete illite dehydroxylation and particle agglomeration. Performance indexes higher than 90%, lime consumption between 554 and 741mgCa(OH)2/g, and the electrical conductivity response ratified the pozzolanic activity. The unique properties achieved by flash-calcination, especially for particles with D90 35 mu m submitted to 970 degrees C in the flash-calcining facility pre-heating, contribute to broadening the calcined clay spectrum for application as supplementary cementitious material, currently dominated by kaolinitic clay.