Concrete strength

[Streetcar]

Anytime you use something in a way it was not designed for you are walking new ground. Buy a culvert (metal, concrete, or plastic) and be done with it worry free.

A beam does not care what it was designed for, but I agree with the second sentence.
A lightly reinforced beam will not be able to support much weight

 

[Streetcar]

But it is a factor in the overall design.

Aggregate size and shape is factor in workability, but the discussion was about concrete strength

 

[Egon]

Aggregate size and shape is factor in workability, but the discussion was about concrete strength

When using rebar agregate size is all part and parcel of the overall design.

 

[rd_macgregor]

Unless there is some other factor militating against it, I would go with the culvert suggestion. It will be easier, cheaper, more trustworthy and make a wider crossing.

 

[Streetcar]

In most cases aggregate size is not considered, during design of reinforced concrete. In rare cases for appearance or clearance issues aggregate can be specified

 

[Renze]

Hmm two guys quabbling over the size of pebbles.. which shows free advice is worth just that...

 

[Egon]

Hmm two guys quabbling over the size of pebbles.. which shows free advice is worth just that...

Right on!:thumbsup:::cool2::cool2:

 

[Cord]

A beam does not care what it was designed for

Yea, but these were columns that were designed to be loaded linearly and the greatest lateral force was to control buckling. The loads were very light because there is so little rebar. Also, notice the design value of the concrete was 4,000 psi, but it tested "not less than 3,300 psi". This means the engineer rejected the concrete and these columns were removed from the building because they were defective.

Honestly, I'd guess that a good drop would crack these "beams".

 

[yanmars]

I anticipate going to a culvert/steel pipe system instead. Thanks for the inputs.

 

[shadetree]

Thank you, I feel better.