Organic chemistry

Alkali metal

Cementitious

Mathematics

Alkali–silica reaction

Endocrinology

Engineering

Chemistry

Metallurgy

Materials science

Geometry

Silicate

Portland cement

Lithium (medication)

Cement

Amorphous solid

Product (mathematics)

Chemical engineering

Medicine

Using Al-rich supplementary cementitious materials to partially replace Portland cement is a well-established empirical approach to mitigate expansion of concrete caused by alkali-silica reaction (ASR). However, the mechanisms behind it are still not completely understood. Synthesis of ASR products in the laboratory provides a unique opportunity to better understand the conditions and mitigation mechanism of ASR. This study focusses on the synthesis of an 10.8 A ASR product, which is structurally identical to the ASR product formed in concrete. The effect of Al and Li on formation of the 10.8 A ASR product is studied. The results show that Al does not prevent the formation of the 10.8 A ASR product, whereas the formation of the 10.8 A ASR product is supressed in presence of Li. At low initial Li/Si an amorphous product is formed and a crystalline lithium silicate at high initial Li/Si ratio.

Synthesis of alkali-silica reaction (ASR) products and the role of Al and Li in mitigating ASR