The American Concrete Institute has released a paper called the Extent of Plasticity in Reinforced Concrete Columns.
Gabriele Guerrini and José I. Restrepo wrote the document. It discusses a method to determine the extent of plasticity at the ends of laterally loaded ductile reinforced concrete columns where plastic hinges form, and where transverse reinforcement is detailed to ensure ductility. Current code formulations are shown to generally underestimate the extent of this region.
ACI says: “An analytical method is derived that combines flexural analysis of the column with flexure-shear interaction considerations.”
The analytical method is compared to the experimental results from tests on reinforced concrete columns conducted over the last 30 years and shows good agreement.
“The paper concludes with simple recommendations for use in design,” ACI adds.
