TITLE:
Dry Mix Slag—High-Calcium Fly Ash Binder. Part One: Hydration and Mechanical Properties
AUTHORS:
Alexey Brykov, Mikhail Voronkov
KEYWORDS:
Ground Granulated Blast-Furnace Slag, Blast-Furnace Slag Activation, High-Calcium Fly-Ash, Sodium Carbonate, Blast-Furnace Slag Binder
JOURNAL NAME:
Materials Sciences and Applications,
Vol.14 No.3,
March
30,
2023
ABSTRACT: High-calcium fly ash (HCFA)—a residue of high-temperature coal combustion at thermal power plants, in combination with sodium carbonate presents an effective hardening activator of ground granulated blast-furnace slag (GGBFS). Substitution of 10% - 30% of GGBFS by HCFA and premixing of 1% - 3% Na2CO3 to this dry binary binder was discovered to give mortar compression strength of 10 - 30 to 30 - 45 MPa at 7 and 28 days when moist cured at ambient temperature. High-calcium fly ash produced from low-temperature combustion of fuel, like in circulating fluidized bed technology, reacts with water readily and is itself a good hardening activator for GGBFS, so introduction of Na2CO3 into such mix has no noticeable effect on the mortar strength. However, low-temperature HCFA has higher water demand, and the strength of mortar is compromised by this factor. As of today, our research is still ongoing, and we expect to publish more data on different aspects of durability of proposed GGBFS-HCFA binder later.