Studying the representative volume of concrete using the entropy weight–grey correlation model

Abstract

The representative volume element (RVE) plays an important role in the study of concrete properties. Meanwhile, RVE size determination itself is an issue that needs further study. For the first time, the problem of determining RVE size based on several factors is regarded as a multi-objective decision-making problem. A new method, the entropy weight–grey correlation model, is proposed, by comprehensively considering the influence of coarse aggregate content, aggregate average particle size and the aggregate fineness modulus. A two-dimensional concrete aggregate specimen, randomly generated by numerical simulation with an aggregate size of 5–20 mm, is taken as a case study, and the RVE size is determined as 6–7 times the maximum aggregate size. Then the finite-element method is used to verify its mechanical properties. This new method has the advantage of depending less on variable data compared to the traditional method, indicating a wider range of applicability. Additionally, the model is applied to determine the RVE size of three-dimensional concrete, which is similar to two-dimensional concrete. It provides a new comprehensive insight for the study of concrete RVE size, which could also be extended to apply to determining the RVE of other composite materials.