Parametric study of functionally graded concretes incorporating steel fibres and recycled aggregates

Even presenting several drawbacks, especially regarding environmental impact, concrete is the most consumed human-made material worldwide. In this sense, incorporating steel fibres and recycled aggregates, and applying the functionally graded material concept may help in the sustainability of concrete. In this paper, relationships between mechanical properties, embodied CO2, cost, among other parameters of functionally graded concretes (FGC) incorporating steel fibres and recycled aggregates were studied. The test results show that the FGC mechanical performance is inferior to fibre reinforced concrete but superior to fibre reinforced recycled aggregate concrete. Therefore, the FGC studied could be used in lower loading capacity applications, such as car parks and cycling lanes. In terms of embodied CO2 and cost, the FGC studied are more affected by the content of fibre than the content of recycled aggregates. Also, equations correlating design and sustainability parameters with reinforced thickness and content of fibre were proposed. (C) 2020 Elsevier Ltd. All rights reserved.