Concrete components are subject to a wide variety of influences depending on the application, so that the composition must be carefully planned. A classification in this regard is made by so-called exposure classes according to Table 1 of DIN EN 206-1 (formerly DIN 1045-2). The exposure class has an influence on the concrete quality, the cover, the permissible crack width and the type of concrete used. The letter X stands for exposure, the following letter for the type of damage and the following number for their intensity. The digits have the following meanings:
0 for Zero RiskC
for CarbonationD
for Deicing SaltS
for SeawaterF
for Frost (possibly with de-icing agent)
A for Chemical AttackM
for Mechanical Abrasion
Examples:
XD3: significant exposure to chlorides, e.g. from road salts on a parking deck
XF1: slight frost attack, e.g. on vertical concrete walls exposed to frost and rain
Source: bauwion
