Comparing Concrete Codes

[alshaiji]

Hi all,
i was asked by my boss to find the minimum steel ratio in concrete columns in more than 5 codes. in the ACI i recall its 1%. i am trying my best to look in the web for other codes. up to now i got NOTHING.
if someone can point out where to find the solution keeping in mind a refrence to the source will be very helpfull.
yours
alshaiji

 

[CottageGuy]

Alshaiji,

The minimum reinforcement for a concrete column in Canada is also 1.0%. This is a requirement of CSA 23.3 (clause 10.9.1).

However, this lower limit can be reduced to 0.5% "provided that the axial and moment resistances are multiplied by the ratio pt/0.01." (ie. if the percentage of steel is 0.75% and your calculated axial resistance is 5 kips, you would have to further reduce the axial resistance by 0.75, to 3.75 kips.). This is described in clause 10.10.5.

In practice, the minimum reinforcement is no lower than 1.0%.

CottageGuy

 

[austim]

AS 3600 1994 (the Australian Concrete Code) also specifies a basic minimum reinfircement area of 1% times the gross area, but offers a reduction for columns which are larger than needed for strength alone (Austim comment - eg if the architect prefers the look of oversized columns).

In that case, the squash load of the reinforcement (Fy*Asc) must exceed 15% of the applied (factored) axial load on the column.

 

[AseismicGuy]

Turkish Code (TS500-2000) imposes the min. reinf. ratio as 0.01 but if the amount of reinf. required for the cross section is increased 30% this limit can be reduced to 0.005.

 

[teisir]

In BS8110 the minimum is 0.4%