abstract
This work explored the effect of mineralogical changes of a modified basic-oxygen furnace slag (BOFS) on the properties of alkali-activated binders. The study quantified the amorphous-crystalline proportions of particles from three different size ranges. These size fractions were finely milled and activated with NaOH solutions. The effects on the reaction kinetics and the mechanical strength of the produced binders were established. The early-stage reaction kinetics were tracked, and the significance of the precursor fraction, the addition of admixtures (gypsum and plasticizer), and the liquid-to-solid ratio (L/S) on the reaction kinetics were identified. The relative variation in the amorphous content between fine and coarse fractions was 45%. These mineralogical differences interacted with the presence of admixtures and the L/S, which impacted the kinetics of the cementitious reactions and the rate of strength development of the binder. Nevertheless, the 30-day strength was similar for all specimens (58 MPa).
keywords
OXYGEN FURNACE SLAG; C-S-H; STEEL SLAG; ALUMINOSILICATE GLASSES; CEMENTITIOUS PROPERTIES; HYDRATION; PHASE; CARBONATION; GYPSUM; BROWNMILLERITE
subject category
Construction & Building Technology; Materials Science
authors
Gonzalez, PLL; Novais, RM; Labrincha, J; Blanpain, B; Pontikes, Y
our authors
João António Labrincha Baptista
Full professor
Rui Miguel Novais
Assistant Professoracknowledgements
This work was part of activities executed for the grant 140514 of the Flemish Institute for the Promotion of Innovation by Science and Technology (IWT) . Pavel L. Lopez G. acknowledges the financial support of the Colombian Administrative Department of Science, Technology and Innovation (COLCIENCIAS) . R.M. Novais wishes to thank FCT (Portuguese Foundation for Science and Technology) for supporting his work (researcher grant Ref. CEECIND/00335/2017) . R.M Novais also acknowledges that this work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/006/2020 financed through the FCT/MEC (PIDDAC) .