Chemical Stability of Aggregate Particles
|
Chemical stability |
Practically stable |
Unstable (activity) |
Examples of activity |
|
Surface reactivity |
Nonreactive or very slightly reactive |
Reactive with formation of unstable products |
Sulphide transformation into sulphates |
|
Reactivity with cement paste |
Noncreative or slightly reactive, nonexpansively reactive |
Reactive with excessive expansion |
ASR, ACR reactivity with alkalies of concrete |
|
Chemical reactivity |
Insensitive to external |
Highly sensitive to environment: oxidizes, hydrates, carbonates, sulphates |
Any mineral that is unstable under surface environment |
|
Volume instability due to ion exchange |
Cation exchange minerals absent |
Cation exchange mineral constituents present |
Sorption of Na from road salt, water sorption causing swelling |
|
Color stability |
Stable |
Unstable, discolours easily |
|
|
Weathering or alteration |
Unreactive |
Reactive |
Quick weathering of sulphides |
