TY - JOUR
T1 - Hydration of potassium citrate-activated BOF slag
AU - Kaja, Anna
AU - Schollbach, Katrin
AU - Melzer, S.
AU - van der Laan, Sieger
AU - Brouwers, H.J.H. (Jos)
AU - Yu, Q.L. (Qingliang)
PY - 2021/2
Y1 - 2021/2
N2 - Basic Oxygen Furnace (BOF) slag is currently utilized with low-grade applications or landfilled. Here, we investigate a novel route to upgrade BOF slag to a high-performance binder by chemical activation with tri-potassium citrate. The impact of tri-potassium citrate on hydration and phase assemblage of BOF slag is analyzed with a multi-technique approach. Results reveal that the addition of tri-potassium citrate considerably enhances the reactivity of brownmillerite and accelerates the hydration of belite at early ages. The majority of brownmillerite hydrates within 24 h, and the reaction kinetics is controlled by the activator dosage. The main products of BOF slag hydration are siliceous hydrogarnet and C-S-H gel. Acting as a strong water reducer, tri-potassium citrate enables the manufacture of slag pastes with high compressive strength (up to 75 MPa at 28 days) and low porosity. Leaching of heavy metals from the slag pastes fulfills the Dutch Soil Quality Decree limits.
AB - Basic Oxygen Furnace (BOF) slag is currently utilized with low-grade applications or landfilled. Here, we investigate a novel route to upgrade BOF slag to a high-performance binder by chemical activation with tri-potassium citrate. The impact of tri-potassium citrate on hydration and phase assemblage of BOF slag is analyzed with a multi-technique approach. Results reveal that the addition of tri-potassium citrate considerably enhances the reactivity of brownmillerite and accelerates the hydration of belite at early ages. The majority of brownmillerite hydrates within 24 h, and the reaction kinetics is controlled by the activator dosage. The main products of BOF slag hydration are siliceous hydrogarnet and C-S-H gel. Acting as a strong water reducer, tri-potassium citrate enables the manufacture of slag pastes with high compressive strength (up to 75 MPa at 28 days) and low porosity. Leaching of heavy metals from the slag pastes fulfills the Dutch Soil Quality Decree limits.
KW - BOF slag
KW - Brownmillerite
KW - Chemical activation
KW - Microstructure
KW - Tri‑potassium citrate
UR - http://www.scopus.com/inward/record.url?scp=85095916811&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2020.106291
DO - 10.1016/j.cemconres.2020.106291
M3 - Article
AN - SCOPUS:85095916811
VL - 140
JO - Cement and Concrete Research
JF - Cement and Concrete Research
SN - 0008-8846
M1 - 106291
ER -