Alkali concentration of cement pore solution and its relation with alkali-silica reaction

To prevent ASR, standards exist to determine safe alkali content levels for typical civil engineering timespans. However, these standards can be misapplied to different applications or timeframes. Other standards define tests, to assess the alkali-sensitivity of granulates by means of expansions tests. These expansion tests might be used to set ad-hoc alkali thresholds, but the reliability in such cases is not assessed. This paper proposes more robust approaches. These approaches are used to define alkali content or concentration thresholds for longer time scales. These newly derived threshold values are then compared with literature values. Additionally it is verified how these values compare to civil engineering standards.