question about concrete02!!!

[DJDJ]

uniaxialMaterial Concrete04 $matTag $fc $ec $ecu $Ec <$fct $et> <$beta>
$matTag integer tag identifying material
$fc floating point values defining concrete compressive strength at 28 days (compression is negative)*
$ec floating point values defining concrete strain at maximum strength*
$ecu floating point values defining concrete strain at crushing strength*
$Ec floating point values defining initial stiffness**
$fct floating point value defining the maximum tensile strength of concrete
$et floating point value defining ultimate tensile strain of concrete
$beta loating point value defining the exponential curve parameter to define the residual stress (as a factor of $ft) at $etu

As we can see, fc defines concrete compressive strength at 28 days, but fc is the concrete cylinder strength or concrete cubic strength? coz different contry use different value to define the concrete compressive strength. In China we use cubic strength but cylinder one is used in the USA.

[ismailqeshta]

We usually put a conservative estimate for concrete cylinders compressive strength as 80% of the cubic strength.

Remember that compressive strength values should be negative.

[DJDJ]

ismailqeshta wrote:
> We usually put a conservative estimate for concrete cylinders compressive
> strength as 80% of the cubic strength.
>
> Remember that the compressive strength values should be negative.

Thx!