A study on geopolymer concrete under elevated temperatures

Vineetha, S and Sudarshan, M S and Shetty, Kiran Kumar (2012) A study on geopolymer concrete under elevated temperatures. In: National Conference on contemporary Civil Engineering Research and Practices, April 20-21, M.I.T, Manipal.

[img] PDF
192.pdf - Published Version
Restricted to Registered users only

Download (425kB) | Request a copy

Abstract

Geopolymer Concrete has the binder formed by alkaline activation of fly ash, whose strength is comparable to that of standard Portland cements. Alkaline activation (AA) of fly ash in aqueous medium at pH>12, when the material sets and hardens, is a process differing from hydration of Portland cement. In the former process (mostly taking place by the .through solution. mechanism) the atoms of Al (and probably also those of Ca) penetrate the originally silicate lattice of fly ash, producing a 2D-3D inorganic hydrated polymer (geopolymer) having the general formula Mn[- (Si - O)z- Al-O]n.wH2O . The hydration products of alkali-activated fly ash are amorphous in character, with prevailing arrangement and minority crystalline phases. The properties of alkali-activated fly ash depend on the way of preparing the mix, in particular on the concentration of the alkaline activator and on ambient moisture conditions. One of the main considerations is that geo polymer concrete needs curing at 600c,especially for early strength, which is difficult to adopt in normal working conditions. Additions of blast-furnace slag to alkali-activated mixes bring about significant increases in strength under normal curing conditions and also the C-S-H phase forms a part from the geopolymeric paste and together gives the binding property to the mix. Such geopolymer concrete mixes with GGBS also show better performance at elevated temperature, compared to geopolymer concrete with fly ash only, as presented here.

Item Type: Conference or Workshop Item (Paper)
Uncontrolled Keywords: Fly ash, Granulated blast furnace slag, geopolymer concrete, elevated temperature, new materials
Subjects: Engineering > MIT Manipal > Civil Engineering
Depositing User: MIT Library
Date Deposited: 03 Sep 2013 11:21
Last Modified: 03 Sep 2013 11:21
URI: http://eprints.manipal.edu/id/eprint/136899

Actions (login required)

View Item View Item