Response of alkali activated fly ash mortars to microwave curing

Jeevaka Somaratna, Deepak Ravikumar, Narayanan Neithalath

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Volumetric heating provided by microwave curing results in faster property development as compared to conventional heat curing that relies on heat conduction from the skin to the core. This paper discusses the compressive strength and microstructure development of microwave cured NaOH activated fly ash mortars, and relates them to the microwave energy absorption by the material which is a function of its dielectric properties. Microwave curing parameters are chosen so as to eliminate the effects of thermal runaway. Strengths that are comparable to or greater than those of mortars heat cured for 48 h at 75 °C are obtained in less than 120 min of microwave curing. The rate of energy absorption by the mortars is found to be relatively constant for a considerable fraction of the microwave curing duration, attributable to the compensation for the drop in dielectric loss factor as a result of moisture loss by the increase in internal electric field. Compressive strength is shown to be related to the microwave energy absorbed by the specimens, especially during the time when free water is present in the system.

Original languageEnglish (US)
Pages (from-to)1688-1696
Number of pages9
JournalCement and Concrete Research
Volume40
Issue number12
DOIs
StatePublished - Dec 2010
Externally publishedYes

Fingerprint

Coal Ash
Alkalies
Mortar
Fly ash
Curing
Microwaves
Energy absorption
Compressive strength
Dielectric losses
Heat conduction
Dielectric properties
Skin
Moisture
Electric fields
Heating
Microstructure
Water

Keywords

  • Alkali activation
  • Compressive strength (C)
  • Fly ash (D)
  • Microstructure (B)
  • Microwave processing (A)

ASJC Scopus subject areas

  • Materials Science(all)
  • Building and Construction

Cite this

Response of alkali activated fly ash mortars to microwave curing. / Somaratna, Jeevaka; Ravikumar, Deepak; Neithalath, Narayanan.

In: Cement and Concrete Research, Vol. 40, No. 12, 12.2010, p. 1688-1696.

Research output: Contribution to journalArticle

Somaratna, Jeevaka ; Ravikumar, Deepak ; Neithalath, Narayanan. / Response of alkali activated fly ash mortars to microwave curing. In: Cement and Concrete Research. 2010 ; Vol. 40, No. 12. pp. 1688-1696.
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