Concrete exposure classification for concrete cover: Eurocode

[Pretty Girl]

I want to know if I did the exposure classification correctly.

Structure Requirements/Detail:
1. Concrete structure with C45/55 Concrete
2. Exposure class XC4
3. Strength class S4: Building structures
3. Need a design working life of 100 yrs
4. It's a member with slab geometry
5. Special quality control of the concrete production ensured.

With the details and requirements considered. I calculated new strength class as follows.

Need a design working life of 100 yrs: Increase class by 2 = +2
Strength class greater than C40/50: reduce by 1 = -1
Member with slab geometry: Yes: reduce by 1 = -1
Special quality control of concrete: Yes: reduce by 1 = -1

New strength class
+2 -1 -1 -1 = -1
So, I reduced class by 1 class. So the new adjusted class = S4-1 = S3

Did I do it correctly?

 

[kieran1]

dont forget an addition to the minimum cover shall be made in design to allow for the deviation ('cdev) usually 10mm

Kieran

 

[CovertShear]

Your calculation makes sense to me, except the last part Special quality control of concrete: Yes: reduce by 1 = -1

The code does not elaborate much on this clause, and I don't use it much.

 

[Pretty Girl]

@kieran1: Thank you. Yeah, I'm aware of that . I was just unsure about the calculation of the classification of strength

@ConvertShear: Thank you. I guess it only applies to very special and closely monitored situations . So the code might not elaborating much on that.