A computational method for selection of optimal concrete recycling strategy

Abstract

Current state-of-the-art concrete recycling technology provides decision makers with the option to produce coarse recycled concrete aggregates (RCAs) with different qualities through variations in the number of crushing stages or the use of beneficiation processes available. Variations in the recycling process may significantly affect the economic and environmental impacts of the concrete recycling strategy. This, together with variations in transportation requirements from one project to another, makes it impossible to draw general conclusions about the sustainability of a concrete recycling strategy. This paper proposes a computational method for identifying the optimal concrete recycling method by considering the trade-off between costs, energy use and carbon dioxide emissions of concrete recycling in a particular project. After estimating the amount of various grades of the recyclable concrete available using the data made available by building information models, a computational algorithm is applied to identify alternative feasible concrete recycling methods to produce different RCA qualities and to estimate the costs, energy use and carbon dioxide emissions associated with each recycling method. The latter will then serve as decision-making criteria for selection of the best feasible concrete recycling method. The proposed computational method is applied to an illustrative example.