TY - JOUR
T1 - Effect of synthesis parameters on the performance of alkali-activated non-conformant EN 450 pulverised fuel ash
AU - Adu-Amankwah, Samuel
AU - Khatib, Jamal M.
AU - Searle, David E.
AU - Black, Leon
PY - 2016/9/15
Y1 - 2016/9/15
N2 - The fly ash reported in this paper is coarser than conventional pulverised fuel ash (PFA), with loss on ignition (LOI) exceeding 10.8%. Consequently, it is precluded from being used as a supplementary cementitious material (SCM) according to EN 450 and disposed in landfills. Alkali-activation of such PFAs is considered here. Three concentrations of sodium hydroxide (NaOH) were separately blended with water glass at different ratios to modify the silica modulus. Heat of reaction, setting time, compressive strength and drying shrinkage were investigated as a function of activator composition. Specimens were either cured at room temperature or hydro-thermally treated at 75 °C for five hours. The results show that by optimizing the activator composition, a binder with a 28 day compressive strength of 25 MPa can be synthesised from such PFAs even at room temperature. Among the activator parameters, the alkali content was observed to be most influential.
AB - The fly ash reported in this paper is coarser than conventional pulverised fuel ash (PFA), with loss on ignition (LOI) exceeding 10.8%. Consequently, it is precluded from being used as a supplementary cementitious material (SCM) according to EN 450 and disposed in landfills. Alkali-activation of such PFAs is considered here. Three concentrations of sodium hydroxide (NaOH) were separately blended with water glass at different ratios to modify the silica modulus. Heat of reaction, setting time, compressive strength and drying shrinkage were investigated as a function of activator composition. Specimens were either cured at room temperature or hydro-thermally treated at 75 °C for five hours. The results show that by optimizing the activator composition, a binder with a 28 day compressive strength of 25 MPa can be synthesised from such PFAs even at room temperature. Among the activator parameters, the alkali content was observed to be most influential.
UR - https://www.sciencedirect.com/science/article/pii/S0950061816308674?via%3Dihub
U2 - 10.1016/j.conbuildmat.2016.05.132
DO - 10.1016/j.conbuildmat.2016.05.132
M3 - Article
SN - 0950-0618
VL - 121
SP - 453
EP - 459
JO - Construction and Building Materials
JF - Construction and Building Materials
ER -