Which size rebar to use?

[MARTINEZ]

I'm fixing to start a big project w/ concrete up to 12 inches thick. How or where do i find out what size (thickness) of rebar needs to be used in the thickers areas of concrete. I also need to know on what centers to use?

I've been using #3 on 18 o.c. For 4inch and #4 on 18o.c. For 6 iinch.

Also this will be for commercial.

Any help would be great

[Richard A Hetzel]

In order to answer your question, we would need a full and complete picture of exactly what this concrete will be for, and what loads it is expected to carry. There is no simple answer, unfortunately.

[concretemasonry]

It all depends on the use. Some codes permit unreinforced concrete because reinforcement may not be needed.

Since someone determined it should be 12" thick (which is quite massive), they should have any idea of the reinforcement needed.

Dick

[MARTINEZ]

I am trying to do a road to a warehouse off of a major street. The thick part is the approach which is 10 inches. There will be loaded 18 wheelers passing thru which is the reason for the thickness.

[Richard A Hetzel]

A civil engineer will be glad to help you with the specifications for such a road. It isn't clear why one part of the road would or should be any thicker or thinner than any other.

[concretemasonry]

You may also check with the people that own the road. In many areas, the municipality does not want reinforcement in an "apron". Usually the amount of reinforcement will relate to the soil and the sub-base under the road and not just the thickness.

I am suprised that if the is a big project there are no plans and specifications. If you are done the job for the owner without plans, I would seriously question the intellegence of the owner using 18 wheelers and the provisions for the owner to pay for the work. If it is on your property, get engineered plans.