In many specifications, quality of water is covered by a clause saying that mixing water should be fit for drinking. What is its significance? Will drinking water always be suitable as mixing water?
The amount of dissolved solids in drinking water is almost always less than 1000 ppm. For a water/cement ratio of 0.5, this corresponds to quantity of solids being about 0.05% of the weight of cement. This quantity is too insignificant to cause any trouble.
However, where drinking water contains a high concentration of sodium or potassium & aggregate-alkali reaction is apprehended , such water should not be used.