Effect of Electrochemical Penetration of Lithium Ions on Concrete Expansion Due to ASR

Abstract

Concrete expansion due to alkali-silica reaction (ASR) is one of the serious deterioration mechanisms of concrete structures. However, no promising repair method for ASR has been established yet. In a bid to remedy this situation, an electrochemical technique to accelerate the penetration of the lithium ions (Li + ) in a lithium-based electrolyte solution into concrete has been developed for the purpose of suppressing ASR-induced expansion due to Li + . From the results of past research work, the penetration area of Li + is limited around the concrete surface and it is difficult to make Li + penetrate into the deeper part of concrete. In this study, experimental investigation was carried out aiming to grasp the influence of the kinds of lithium salts and the temperature of the electrolyte solution on the migration properties of ions in concrete and ASR-induced expansion of concrete. The electrochemical migration of Li + was found to accelerate with rises in temperature and the effective diffusion coefficient of Li + increased three times with changes in temperature from 20˚C to 40˚C in the case of a Li 2 CO 3 electrolyte solution. Moreover, ASR-induced expansion of concrete after this treatment was suppressed compared with the case of non-treated specimens.

Damage to Concrete Structures

“…However, application of these special chemical admixtures remains very limited until now, probably because of the high cost. Lithium treatment of ASR-affected existing structures in order to stop ongoing ASR has also been investigated (Ueda et al 2011), but this is beyond the scope of this textbook.…”

Toward Durable, Reliable and Innovative Concrete Structures

“…For reducing such risk, electrochemical introduction of lithium ions by using lithium-based electrolyte solution has been investigated (Ashida et al 1999;Whitemore and Abbott 2000) expecting the effect of suppressing ASR-induced expansion of concrete (MacCoy and Caldwell 1951;Diamond and Ong 1992;Lumley 1997). Past investigations (Souza et al 2017;Ueda et al 2005Ueda et al , 2006Ueda et al , 2011Folliard et al 2008) found that the ASR-induced expansion of concrete after the electrochemical treatment tended to be suppressed compared with the non-treated case mainly around the exposed surface.…”