Comparison between Eurocode 2, ACI 209R-92 and Gardner&Lockman Models in Creep Analysis of Composite Steel-Concrete Section

Abstract

<p> The paper presents analysis of the stress-strain behaviour and deflections changes due to creep in statically determinate composite steel-concrete beam according to EUROCODE 2, ACI209R-92 and Gardner&Lockman models. The mathematical model involves the equation of equilibrium, compatibility and constitutive relationship, i.e. an elastic law for the steel part and an integral-type creep law of Boltzmann – Volterra for the concrete part considering the above mentioned models. On the basis of the theory of the viscoelastic body of Maslov-Arutyunian–Trost-Zerna-Bažant for determining the redistribution of stresses in beam section between concrete plate and steel beam with respect to time “t”, two independent Volterra integral equations of the second kind have been derived. Numerical method based on linear approximation of the singular kernel function in the integral equation is presented. Example with the model proposed is investigated.</p>

08.53: Integral analysis of steel concrete beams, Regarding creep of concrete according EC2, versus (AAEMM) of bažant

“…The method is also much more accurate than the rate -of -creep method [11]. In the paper [15] using the mathematical model in Fig.1, the authors introduce the system of linear Volterra integral equation of second kind and obtain the results from their numerical solutions. The kernels of the integral equations contain the respective creep functions corresponding to the models: EC2, ACI209-R2 and G&L [1].…”

“…For constant elasticity module of concrete strain compatibility on the contact surfaces between the concrete and steel members of composite girder is as following: (15) Here is the place to explain the meaning of the second term of the integral relations (14)(15). This type of integral, known as a hereditary integral of Stieltjes expresses time history of loading.…”