Concrete_Stress_Strain

This calculation shows the predicted stress-strain relationship of concrete by Popovics, Thorenfeldt, and Collins (shown in "Prestressed Concrete Structures" by Collins and Mitchell). Stress distributions are often modeled by the Whitney Stress Block, which is an adequate assumption for most design purposes. However, these equations allow calculation of a more precise distribution of stresses to allow for a more refined analysis.

Calculation Reference
Concrete
Concrete Design