ABSTRACT
ABSTRACT. The concrete mix of reinforced structures in water treatment plants can be designed in agreement with the durability criteria of the European prestandard ENV 206. According to this norm, plain, reinforced and prestressed concrete structures o f these plants can be segmented into three different types:
i) those which are not in contact with liquid water and therefore belong to either exposure class 2a (humid air) or exposure class 2b (humid environment with frost) depending on the local climate;
ii) those which are in contact with non aggressive liquid water and should be produced by using a watertight concrete;
iii) those which are in contact with water containing aggressive chemicals (ammonium, carbon dioxide, etc.) and therefore belong to one of the exposure class 5a, 5b or 5c (depending on the specific type and concentration of the chemical aggressive agent).
