Modeling Strategy to Simulate Recycled Concrete Structures in a Physically Nonlinear Analysis

Resumo

In order to mitigate the environmental impacts caused by the construction industry, efforts have been made to minimize the production of waste and to promote its reuse in different applications, including construction projects. This reuse of construction and demolition waste is not only a sustainable practice but also economically attractive for the industry, combining waste reduction, decreased extraction of raw materials, and lower expenditure on the acquisition of new inputs. Concrete is a material widely used in construction and, consequently, large quantities of it are found among construction and demolition waste. One option for the circular use of concrete waste is its partial substitution for natural coarse aggregates (gravel) in conventional concrete, resulting in what is known as recycled aggregate concrete. Currently, numerous experimental studies are underway to evaluate the potential and applicability of recycled concrete. However, there remains a gap in the literature regarding computational modeling aimed at better understanding the mechanical behavior of this new material. In response to this demand, the present work presents a strategy to simulate recycled concrete structures, accounting for its heterogeneity by explicitly representing the mainly constituent phases, namely, the cementitious matrix of conventional concrete, the natural coarse aggregate, and the recycled concrete aggregate—which includes the recycled cementitious matrix and recycled gravel. The computational modeling will be performed using the finite element method, employing nonlocal damage models to represent material degradation, thereby preventing spurious localization phenomena typically observed in refined meshes. Through this study, it is intended to foster the development of further research dedicated to recycled concrete, so that, by combining experimental and numerical investigations, its behavior and limitations can be thoroughly understood, promoting its widespread use while ensuring structural safety and high performance.