Concrete compressive stress limitation at SLS: the value of k1 and the maximum increase in the stress limit
Eurocode 2 part 2: Design of concrete bridge structures 7.2 (102)
Longitudinal cracks may occur if the stress level under the characteristic combination of loads exceeds a critical value. Such cracking may lead to a reduction of durability. In the absence of other measures, such as an increase in the cover to reinforcement in the compressive zone or confinement by transverse reinforcement, it may be appropriate to limit the concrete compressive stress to a value k1fck in areas exposed to environments of exposure classes XD, XF and XS (see Table 4.1).
The recommended value of k1 for the concrete compressive stress limitation is 0,6. The recommended maximum increase in the stress limit is 10 %.