different types of water reducers
 

different types of water reducers
can somebody explain to me what is the difference between, normal, mid range, and high range water reducers?
thanks!

water reducing admixtures change the properties of fresh concrete, but still allow a predictable and acceptable final product. they allow they allow concrete to be batched in either of two ways:
1. use less water but the concrete retains expected workability. within reason, less water tends to give stronger concrete.
2. use the specified amount of water but the concrete will have improved flowabilty without loss of air entrainment or slowing the setting time.
the words you reference, "normal", "mid range" & "high range" are relative measures of how much effect each product has on the concrete. since each admixture manufacturer has their own definition of what those words mean, it is not really possible to give specific "generic" definitions.
astm c494 "standard specification for chemical admixtures for concrete" gives the following definitions:
water-reducing admixture - an admixture that reduces
the quantity of mixing water required to produce concrete of a given consistency.
water-reducing admixture, high range — an admixture
that reduces the quantity of mixing water required to produce concrete of a given consistency by 12 % or greater.