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

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

Shi, Zhenguo (Swiss Federal Laboratories for Materials Science and Technology (Empa), Switzerland)
Lothenbach, Barbara (Norwegian University of Science and Technology (NTNU), Norway)

2021-04-29

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 Å 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 Å ASR product is studied. The results show that Al does not prevent the formation of the 10.8 Å ASR product, whereas the formation of the 10.8 Å 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.

Lithium
Alkali-silica reaction
Mitigation
Synthesis
Aluminium

http://resolver.tudelft.nl/uuid:b7b8f07a-14e3-429e-88dd-0f0da6479615

Conference proceedings

conference paper

(c) 2021 the authors