40cm (15.7inch) spacing of tension bars in 100cm (39.4inch) thick mat foundation?

[drile007]

Hello everyone,

I'm wondering if there are any concerns in placing Ø25 (#8) longitudinal/tension bars in 40cm (15.7inch) spacing in 100cm (39.4inch) thick mat foundation? This reinforcement will be placed in foundation areas where bending moments do not exceed cracking moments (the resistance moment without any reinforcement->just taking into account concrete tension resistance). on other areas the reinforcement will be much higher.
According to Eurocode, the fi25/40cm= satisfy the minimum condition for longitudinal/tension steel area to control cracking? Code only restricts minimum distance between tension bars, not maximum?
Are there any other restrictions (besides cracking)?

Any thoughts are highly appreciated

 

[HTURKAK]

I understand your approach . Pls look Tabel 7.3N Maximum bar spacing for crack control and i will suggest you to use max. spacing 250 mm.

My approach for 100cm thick mat foundation would be,
- Provide min. 0.0035Ac reinf . for span rein. ( top reinf., everywhere ) 100*100*0.0035= 35 cm2 ( T20/175 mm BOTH WAYS )
- Provide min. 0.002 Ac reinf . for bottom rein. ( bottom reinf., everywhere ) 100*100*0.002= 20 cm2 ( T16/200 mm BOTH WAYS )
- Provide supplementary bottom reinf. under columns.

..........


He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48