Field bending of rebar

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Does anyone know of any resources outlining limitations of field bending rebar? I have a footing poured with exposed vertical dowels to tie-in the foundation wall above. The foundation wall is to be backfilled on both sides up to FF elev of the slab. The vertical bars were bent 70-75 degrees, to facilitate access into the structure, and then straightened back to vertical. I am looking for information either confirming or denying this practice.


7.3 ACI 318 covers bending of rebar but leaves field bending of rebar up to the engineer. Babaei and Hawkins wrote a good article called “Field Bending and Straightening of Reinforcing Steel” in the January 1992 issue of the magazine Concrete International printed by ACI. This article is very good. It goes in-depth about heating bars for bending. I have uploaded a few pages from PCA Notes on ACI 318 that addresses field bending. This should do but I also recommend the article so you really know the process and then you can direct the contractor better. I usually photocopy both the article and the PCA pages and give them to the contractor and inspector.

To sum it up, you can field bend bars up to No. 11’s. You need to apply heat to bars No. 6 and larger. For bars No. 5 and smaller you do not need to apply heat to bend a straight bar. You do need to apply heat to No. 5 bars and smaller if they were previously bent.