Concrete Design

[KCEngineer]

Trying to decide when I can drop the minimum steel requirement in design. For instance, vertical piers for a house. Minimum steel puts the design way over...

 

[csd72]

My rule is normally if it wont collapse when the reo fails then it is okay to use less than minimum reo.

 

[msquared48]

I'm in a high seismic area, and generally put in the mininum steel regardless.

Here, technically even 1'-6" square spread footings require bending reinforcing steel. I admit that with shear controlling the design, and with not enough development length to develop the tension in the steel, it is ridiculous, but I do it anyway in most cases. In small strip footings, to get the horizontal steel, I will just put a 4" to 6" bend on the wall dowels and alternate the bends in the strip footing. Works for me.

Mike McCann
McCann Engineering

 

[RHB51]

Have you considered looking at it as "plain" concrete?
Residential designs generally can be designed per the plain concrete section of ACI318.

 

[sdz]

As RBH says you can design as plain concrete. But have you considered all possible loads including accidental and construction loads? Personally I would use minimum reinf and sleep well.

 

[swivel63]

you can use half of minimum if it's sized for architectural purposes, i believe.

 

[turnitup]

Are you going to live in it? It is Cheep insurance, Go with engineering. Whats a few hundred more dollars, compared to the total investment of the house?