Creep and Shrinkage Effects

RAM Concept considers creep and shrinkage in any cross section by modifying the concrete stress-strain curves to be:

σ = f((ε - ε_cs )/ k_c)

where

σ	=	stress in concrete
k_c	=	concrete creep factor (typically 3.35 = 2.35 + 1.0)
ε	=	strain in cross section
ε _cs	=	shrinkage strain
f()	=	concrete material short-term stress-strain curve

This modified concrete stress-strain curve is only used in the ECR calcs. It is never used for gross-section or cracked-section stress predictions.

Note: ACI 209 reports the value of 3.35 as an average creep value. RAM Concept files adopt this value as a default.