Concrete strenght
Concrete strenght
(OP)
Hi guys!
I need some help on this.
You know that the concrete class is defined by the fractal 5% value (or 0.05).
I need some clear guidelines on how to do this, with exact formulas and an example.
If I have some concrete strenght values resulted from concrete cubes with class C20/25, like: 24.1; 26.2; 30.1; 23.6; 21.5; 20.2 [MPa].
How do I calcultate de 5% fractal (fck 0.05)to see if it's above 25MPa ???
I need exactly how to calculate, because this is just an example and I have a lot of values.
Thank you.
I need some help on this.
You know that the concrete class is defined by the fractal 5% value (or 0.05).
I need some clear guidelines on how to do this, with exact formulas and an example.
If I have some concrete strenght values resulted from concrete cubes with class C20/25, like: 24.1; 26.2; 30.1; 23.6; 21.5; 20.2 [MPa].
How do I calcultate de 5% fractal (fck 0.05)to see if it's above 25MPa ???
I need exactly how to calculate, because this is just an example and I have a lot of values.
Thank you.





RE: Concrete strenght
RE: Concrete strenght
RE: Concrete strenght
RE: Concrete strenght
Basically, you will do something like this: Required Mix Strength (characteristic strength) = required strength + (1.65)(stdev). Typically stdev=5 if the batch plant stdev is not known. If you need 30 MPa, then characteristic strength = 30+(1.65)(5) = 30+8.2 = 38 (I wouldn't go into the worry about the 0.2). Some books/codes acually give you the added strength to the required strength. So, you achieve 38 MPa on the average strength and only 5% would be less than 30 MPa.
RE: Concrete strenght
RE: Concrete strenght