Impact of integrating plastic wastes in concrete mixtures on the mechanical properties and the shear behavior of RC beams

Abstract

A significant quantity of plastic wastes is produced each year. Wastes are considered as one of the most dangerous problems that could destroy the environment. This problem is generally the result of discarding these wastes in improper places. For this, we can incorporate recycled wastes into the concrete mixtures of beams in order to give the beams a good resistance before the first crack’s appearance and to give them the ability to resist big loads. For this and to be able to examine the mechanical properties of PET which will be used in concrete, numerous experimentations were tested, but limited finite element studies were examined. This research aims to numerically model a reinforced lightweight concrete beam under the 4-point bending system. Various mixes with various PET rates were utilized. The used rates of PET were 1.5,2,3, and 4.5%. The concrete’s behavior was described by the Mazars damage model. The spatial variability of concrete's mechanical properties was increased by the incorporation of PET. This variability was numerically introduced using Gaussian random fields method. To reproduce the mechanical behaviors of concrete having recycled PET, the stochastic finite element models were found to be a reliable tool. The mean and standard deviation of the maximum force as well as for the maximum deflection of a RC beam having various PET rates ranging between 0 and 4.5% were predicted using the stochastic finite element method.