Fluidized bed combustion (FBC)waste is generally unsuitable for making ordinary cements and concretes, and its alternative uses are therefore worthy of consideration. In the presentwork, FBCwaste is investigated as a potentially suitable single raw material for the manufacture of building components based on ettringite, a compound characterized by low density, high fire resistance, significant mechanical strength and usefulness as the main component of preformed lightweight building materials. The hydration behaviour of two FBC waste samples (a fly and a bottom ash) was explored within curing periods comprised between 2 and 24 h at 55 °C, 70 °C and 85 °C. X-ray diffraction and differential thermal analysis were employed as main experimental techniques in order to evaluate the distribution of the hydration products. The role of the rawash chemical and mineralogical composition, operating temperature and time in the ettringite formation was highlighted. The fly ashwasmore prone to generate ettringite which, after 2 h-curing time, tended to form and decompose earlier, as the curing temperature and time were further increased. The selectivity of the reactants toward ettringite can be enhanced by the addition of blending components.

Study of the hydrothermal treatments of residues from fluidized bed combustors for the manufacture of ettringite-based building elements

TELESCA, ANTONIO;CALABRESE, DANIELA;MARROCCOLI, Milena;
2014-01-01

Abstract

Fluidized bed combustion (FBC)waste is generally unsuitable for making ordinary cements and concretes, and its alternative uses are therefore worthy of consideration. In the presentwork, FBCwaste is investigated as a potentially suitable single raw material for the manufacture of building components based on ettringite, a compound characterized by low density, high fire resistance, significant mechanical strength and usefulness as the main component of preformed lightweight building materials. The hydration behaviour of two FBC waste samples (a fly and a bottom ash) was explored within curing periods comprised between 2 and 24 h at 55 °C, 70 °C and 85 °C. X-ray diffraction and differential thermal analysis were employed as main experimental techniques in order to evaluate the distribution of the hydration products. The role of the rawash chemical and mineralogical composition, operating temperature and time in the ettringite formation was highlighted. The fly ashwasmore prone to generate ettringite which, after 2 h-curing time, tended to form and decompose earlier, as the curing temperature and time were further increased. The selectivity of the reactants toward ettringite can be enhanced by the addition of blending components.
2014
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11563/92697
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 14
  • ???jsp.display-item.citation.isi??? 10
social impact