steels to mass concrete cracking 1

[jymac]

Hello all,
I got a question in designing reinforced mass concrete: I have calculated amount of steel needed to limit the crack width according to ACI 207.2R, what do I do next? shall I just add the amount of steel on to flextural steel (which is calculated due to flexture) or just pick the amount whoever is higher? (ex. pick structural steel or cracking steel whoever is higher) TIA.

Greetings,

new civil grad

 

[frv]

Whichever amount controls.

 

[jymac]

thanks frv,
in this case, steels that limiting crack widths are always in the direction where min. flextural steel are present (horizontal steel in a wall), if this is the case, I would probably just go for cracking steel if the amount are higher than flextural steel? thanks again

 

[kslee1000]

Try use smaller bars with smaller bar spacing. It will help to minimize the crack width.

 

[asixth]

You should have two values for the amount of steel reinforcement:

1) Area of steel for flexural requirements
2) Area of steel required for crack control.

Tensile steel needs to be provided for flexure and should go in the tension face accordingly.

The crack control steel can be distributed between both faces in any proportion. As long as both these requirements are satisfied, your okay.

I agree with kslee1000, try to keep your spacing less than 1' or 300mm.