Behavior characteristic of lithium ion in alkali-aggregate reaction

The behavior characteristic of lithium ion during the procedure of alkali-aggregate reaction has been thoroughly studied on the base of investigation of mineral characteristic of siliceous carbonate aggregate by X-ray diffraction analysis, chemical composition analysis and polarization microscope analysis. Concrete prism testing (according to CSA A23.2-14A or ASTM C 1293) results show that when LiNO₃ is added at the dosage of 1.11 [Li]/[Na+K] molar ratio, the alkali-aggregate reaction of concrete can be suppressed effectively. Meanwhile, when lithium glass is added, the expansion may even increase to some extent. Compared to the single addition of mineral admixtures (either fly ash or slag), the composition addition of lithium with them increases the inhibition effect. The competition between Li⁺ and Na⁺, K⁺ exists during the alkali-aggregate reaction of concrete. Comparatively, Li⁺ has some superiority. This is in accordance with the concrete expansion inhibition effect of lithium salts. In addition, results of compressive strength comparison show that concrete strength will decrease due to the addition of lithium.