Self-compacting concrete with recycled aggregates: Mechanical properties and effective porosity

Abstract

Self-compacting concrete (SCC) is a type of concrete with high flowability that allows it to be poured without the need for vibration. One of many ways to increase its sustainability is its manufacturing with recycled aggregates (RA). The addition of these sustainable aggregates modifies both the fresh and hardened behavior of SCC, when a proper balance between these two dimensions being key to its successful use. This chapter analyzes the effect of the use of RA in SCC by means of an experimental campaign in which SCC mixes were made with different contents of coarse and/or fine RA. On the one hand, it is shown that an adequate adjustment of the mix composition allows obtaining the maximum flowability levels in the SCC with RA from a slump-flow approach. On the contrary, the variations of the mechanical properties caused by each content of each RA fraction are analyzed, as well as the significance of the interaction between the effects of both fractions. Finally, the effective porosity of SCC with RA is evaluated through capillary water absorption, demonstrating its usefulness to assess the mechanical behavior of this type of concrete. The objective of this chapter is to provide the reader with an overview of the behavior of SCC with RA, to realize that the complete mechanical behavior of this concrete type can be assessed by using a simple parameter such as porosity. © 2025 Elsevier Ltd. All rights reserved.