Alkaline Activation of Blended Cements with Calcined Illitic Clay Using Glass Powder Wastes

RAHHAL, VIVIANA F.; TREZZA, MÓNICA A.; IRASSAR, EDGARDO F.

RILEM Bookseries

Springer

Año: 2020 vol. 25 p. 115 - 124

2211-0844

Previous studies revel that calcined illitic clay acts as potentially supplementary cementitious materials in Portland cement. Packing and workability are improved; the hydration products are like that corresponding to Portland cement and it also produces a pore size refinement improving the mechanical performance at later ages. The illitic clays have a high activation temperature and its pozzolanic activity is slow; however, it is the most abundant type of clay in several regions of the world, and therefore, their used as supplementary cementitious materials must be improved. Therefore, compression resistance values denote the effect of dilution at early ages. On the other hand, materials containing silica and alumina can be activated in an alkaline form, which would help to compensate the dilution generated by the addition. In this work, the alkaline activation of cement mixtures with calcined illitic clays is presented. As an alkaline activator, finely ground discarded glass is used. The finely ground glass, due to its amorphous nature, reacts quickly contributing to early hydration, while providing the alkalis necessary for an alkaline activation. In this paper, the blended cements with 30% of calcined illitic clays were analyzed and the effect of different percentages of replace by glass powder wastes was studied.