High-Rise Building Design Using Midas Gen

CColumn-ShorteningColumn ShorteningElastic and Inelastic Column ShorteningInelastic Shortening = Creep + ShrinkageCreepShrinkageCreep is time-dependent increment of strain under sustained stress.‣Basic creep occurs under the condition of no moisture movement to and from the environment.‣Drying creep is the additional creep caused by drying.Drying creep has its effect only during the initial period of load.As per EN1992-1-1:2004, the total shrinkage strain is composed oftwo components, the drying shrinkage strain and the autogenousshrinkage strain.‣Drying Shrinkage(εcd) is due to moisture loss in concrete.‣Autogenous Shrinkage(εca) is caused by hydration of cement.As per EN1992-1-1:2004, the creep deformation of concrete is predicted as follows:Where,t 0 = Age of the concrete at first loading in daysE c = Tangent modulus, 1.05Ecmσ c = Constant compressive stress at time t=∞Where,k h = coefficient depending on the notional size h0t = age of the concrete at the moment consideredt s = age of the concrete (days) at the beginning of drying shrinkage14