Artículos de revistas
Mechanical properties, drying and autogenous shrinkage of blast furnace slag activated with hydrated lime and gypsum
Fecha
2010Registro en:
CEMENT & CONCRETE COMPOSITES, v.32, n.4, p.312-318, 2010
0958-9465
10.1016/j.cemconcomp.2010.01.004
Autor
MELO NETO, Antonio A.
CINCOTTO, Maria Alba
REPETTE, Wellington
Institución
Resumen
This article reports the characteristics of blast furnace slag (BFS) pastes activated with hydrated lime (5%) and hydrated lime (2%) plus gypsum (6%) in relation to compressive strength, shrinkage (autogenous and drying) and microstructure (porosity, hydrated products). The paste mixtures were characterized using powder X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and thermogravimetric analysis (TG/DTG). BSF activated with lime and gypsum (LG) results in larger amounts of ettringite when compared with BFS activated with lime (L). Although the porosities of the L and LG mixtures were about the same, there was a greater pore refinement for the BFS activated with lime, with an increase in mesopores volume with age. The presence of ettringite and the higher volumes of macropores cause the compressive strength of BSF activated with hydrated lime plus gypsum to be smaller than that of BFS activated with lime. For both chemical activators, compressive strength developed slowly at early ages. Autogenous and drying shrinkage were greater for the BFS activated with lime, believed to result from the more refined porous structure in comparison with the mixture activated with gypsum plus lime. (c) 2010 Elsevier Ltd. All rights reserved.