TY - JOUR
T1 - Thermodynamic modelling of BFS-PC cements under temperature conditions relevant to the geological disposal of nuclear wastes
AU - Prentice, Dale P.
AU - Walkley, Brant
AU - Bernal, Susan A.
AU - Bankhead, Mark
AU - Hayes, Martin
AU - Provis, John L.
PY - 2019/5/31
Y1 - 2019/5/31
N2 - Intermediate level waste produced in UK nuclear power generation is encapsulated or immobilised in blended cements comprising blast furnace slag (BFS) and Portland cement (PC), to be emplaced in a proposed geological disposal facility (GDF). The wasteforms are expected to be exposed to temperatures from 35 to 80 °C during the initial 150 years of GDF operation. Thermodynamic modelling is applied here to describe the phase assemblages of hydrated 1:1, 3:1 and 9:1 BFS-PC blends, with the participation of hydrogarnet as an important phase above 60 °C. The chemical composition of the main phase forming in these systems, an aluminium rich calcium silicate hydrate (C-A-S-H), was well described by a solid-solution model with explicit Al incorporation, although the Al/Si ratio was systematically slightly under-predicted. The developed thermodynamic model predicts the correct phase assemblage across varying temperature regimes, making it a valuable tool to assess the effects of temperature on cements.
AB - Intermediate level waste produced in UK nuclear power generation is encapsulated or immobilised in blended cements comprising blast furnace slag (BFS) and Portland cement (PC), to be emplaced in a proposed geological disposal facility (GDF). The wasteforms are expected to be exposed to temperatures from 35 to 80 °C during the initial 150 years of GDF operation. Thermodynamic modelling is applied here to describe the phase assemblages of hydrated 1:1, 3:1 and 9:1 BFS-PC blends, with the participation of hydrogarnet as an important phase above 60 °C. The chemical composition of the main phase forming in these systems, an aluminium rich calcium silicate hydrate (C-A-S-H), was well described by a solid-solution model with explicit Al incorporation, although the Al/Si ratio was systematically slightly under-predicted. The developed thermodynamic model predicts the correct phase assemblage across varying temperature regimes, making it a valuable tool to assess the effects of temperature on cements.
UR - http://www.scopus.com/inward/record.url?scp=85061527945&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2019.02.005
DO - 10.1016/j.cemconres.2019.02.005
M3 - Article
AN - SCOPUS:85061527945
SN - 0008-8846
VL - 119
SP - 21
EP - 35
JO - Cement and Concrete Research
JF - Cement and Concrete Research
ER -