Numerical modeling of a reinforced concrete beam with and without expanded polystyrene beads

Abstract

Waste included concrete have been intensively studied recently to help decrease the effect of wastes in landfills and reduce pollution forms (land, air, or water). Introducing wastes in concrete helps in reducing the consumption of raw materials, where various studies has proven its benefits as a good replacement of concrete components. Recycled Expanded polystyrene (EPS) beads, a form of plastic, is a lightweight waste used in lightweight concrete as replacement of aggregates. Several experimental studies have been done to test the mechanical properties of EPS concrete, but few numerical finite element studies have been tested. The objective of this work is to numerically model reinforced lightweight concrete beams subjected to 4-point bending. Several mixtures have been used, such as medium strength concrete with 0, 2 and 3 kg/m3 EPS. Mazars damage model with stress-based non local approach have been used to describe the behavior of concrete. The use of EPS increases the spatial variability of concrete mechanical properties (tensile strength and Young’s modulus). Thus, this variability is numerically introduced using Gaussian random fields on these mechanical properties. Stochastic finite element models proved to be an accurate tool to reproduce the mechanical behavior of concrete with recycled EPS. This method allowed the prediction of mean and standard deviation of the maximum force and the maximum deflection for beams subjected to 4-point bending, for concrete having EPS weight ranging between 0 and 3 kg/m3