TY - JOUR
T1 - Effect of nanosilica-based activators on the performance of an alkali-activated fly ash binder
AU - Rodríguez, E.D.
AU - Bernal, S.A.
AU - Provis, J.L.
AU - Paya, J.
AU - Monzo, J.M.
AU - Borrachero, M.V.
PY - 2013/1/1
Y1 - 2013/1/1
N2 - This paper assesses the effect of the use of an alternative activator based on nanosilica/MOH (M = K+ or Na+) blended solutions on the performance of alkali-activated fly ash binders. Binders produced with commercial silicate activators display a greater degree of reaction, associated with increased contents of geopolymer gel; however, mortars produced with the alternative nanosilica-based activators exhibited lower water demand and reduced permeability, independent of the alkali cation used. Na-based activators promote higher compressive strength compared with K-based activators, along with a refined pore structure, although K-activated samples exhibit reduced water demand. Zeolite type products are the major crystalline phases formed within these binders. A wider range of zeolites is formed when using commercial silicate solutions compared with the alternative activators. These results suggest that there are variations in the availability of Si in the system, and consequently in the alkalinity, depending on the silicate source in the activator, which is important in determining the nanostructure of the geopolymer gel.
AB - This paper assesses the effect of the use of an alternative activator based on nanosilica/MOH (M = K+ or Na+) blended solutions on the performance of alkali-activated fly ash binders. Binders produced with commercial silicate activators display a greater degree of reaction, associated with increased contents of geopolymer gel; however, mortars produced with the alternative nanosilica-based activators exhibited lower water demand and reduced permeability, independent of the alkali cation used. Na-based activators promote higher compressive strength compared with K-based activators, along with a refined pore structure, although K-activated samples exhibit reduced water demand. Zeolite type products are the major crystalline phases formed within these binders. A wider range of zeolites is formed when using commercial silicate solutions compared with the alternative activators. These results suggest that there are variations in the availability of Si in the system, and consequently in the alkalinity, depending on the silicate source in the activator, which is important in determining the nanostructure of the geopolymer gel.
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84870440003&partnerID=MN8TOARS
U2 - 10.1016/j.cemconcomp.2012.08.025
DO - 10.1016/j.cemconcomp.2012.08.025
M3 - Article
SN - 0958-9465
VL - 35
SP - 1
EP - 11
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
IS - 1
ER -