Plain Concrete Walls Allowable Flexural Stress
Plain Concrete Walls Allowable Flexural Stress
(OP)
The formula I have used for flexural stresses in plain concrete walls is 5 x Square Root f'c x Section Modulus. I understand this value has increased due to empirical results obtained from many homes built without any foundation wall stress cracks. Does anyone have the ACI new formula. Is it now 7.5 instead of 5??. Any info will be appreciated. Thanks.






RE: Plain Concrete Walls Allowable Flexural Stress
The "allowable" stress that you mention is for cracking in prestressed concrete, and you can find that in the PCI manual. It is not meant to be used as an allowable stress for unreinforced concrete.
The idea for using that value in precast is that quite often the precast will be architecturally exposed (columns), or you want to check cracking in the section, but you still have the reinforcement in the prestressing.
RE: Plain Concrete Walls Allowable Flexural Stress
RE: Plain Concrete Walls Allowable Flexural Stress
I think the new ACI332-04 Code for plain concrete foundation walls allows a new 50% increase for flexure. I don't have that code and I am just looking for verification.
Thanks.
RE: Plain Concrete Walls Allowable Flexural Stress
RE: Plain Concrete Walls Allowable Flexural Stress