Impede® LN is a lithium nitrate based admixture designed to mitigate ASR (alkali-silica reactivity) in concrete. Since the early 1950’s Lithium compounds have shown an ability to control ASR. These findings were confirmed by the Strategic Highway Research Program (SHRP). ASR occurs when reactive silica, found in aggregates, is supplied with moisture and alkalis. An expansive gel is then created which results in cracking and premature deterioration of concrete.
When using Impede® LN at recommended dosages ASR can be controlled. Dosages will vary depending on the sodium equivalent of cement (total alkali) and the addition of pozzolans such as Type F Fly Ash, GGBFS, and or silica fume.