Effect of LiNO(3) on Expansion of Alkali–Silica Reaction in Rock Prisms and Concrete Microbars Prepared by Sandstone

The aim of this research is to investigate the effect of LiNO(3) on the alkali–silica reaction (ASR) expansion of reactive sandstone and the mechanism through which this occurs. This paper presents the results from tests carried out on rock prisms and concrete microbars prepared by sandstone and LiNO(3). The findings show that LiNO(3) does not decrease the expansion of these samples unless the molar ratio of [Li]/[Na + K] exceeds 1.66, and the expansion is greatly increased when its concentration is below this critical concentration. The expansion stress test proves that Li(2)SiO(3) is obviously expansive. X-ray diffraction (XRD) and scanning electron microscope (SEM) results indicate that LiNO(3) reacts with the microcrystalline quartz inside sandstone, inhibiting the formation of ASR gel, and the formation of Li(2)SiO(3) causes larger expansion. A high concentration of LiNO(3) might inhibit the ASR reaction in the early stages, and the formation of Li(2)SiO(3) causes expansion and cracks in concrete after a long period of time.