Open AccessShotcrete using ternary binder made from coal combustion products: from lab tests to an application
Author(s) -
Vít Šmilauer,
Radoslav Sovják,
Šárka Pešková,
Rostislav Šulc,
František Škvára,
Martina Šídlová,
Roman Snop,
P. Růžička
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1205/1/012004
Subject(s) - ettringite , shotcrete , portland cement , fly ash , ternary operation , materials science , metallurgy , cement , combustion , coal , composite material , waste management , engineering , geotechnical engineering , chemistry , computer science , organic chemistry , programming language
The paper presents a ternary binder development and its utilization in shotcrete. The binder is made from fluidized bed combustion (FBC) fly ash, siliceous fly ash, and Ca(OH) 2 addition, now available under the name Sorfix. XRD and TGA identified ettringite and C-S-H as two main hydration products. In addition, thermodynamic modeling verified robustness in terms of space-filling capabilities when varying input oxide composition. Since alkali-free accelerators produce mostly ettringite in Portland-based systems, a fraction of Portland cement was advantageously replaced with the ternary binder, forming early ettringite as well. Extensive testing led to 45% replacement of Portland cement, following J2 curve for early strength gain used commonly in shotcrete tunnel linings. The shotcrete was successfully tested in a mock-up experiment in a 2 m 3 Prague served for the full-scale application, utilizing over 1000 tons of Sorfix and saving over 700 tons of CO 2