Nanomodified Low‐Carbon Recycled Aggregates Concrete with Enhanced Durability Performance

Abstract

The article presents the low‐carbon recycled aggregate concrete (RAC) with improved technical properties. The feasibility of nanomodification of fine fraction of recycled aggregate is shown. The use of recycled concrete aggregate (RCA) is associated with an increase in porosity, structural heterogeneity and weakening of the interfacial transition zone (ITZ), which may adversely affect the mechanical properties and durability of concrete. To overcome these limitations, cementitious systems containing Portland cement CEM II/A‐LL 42.5R and combined pozzolanic additive based on fly ash and silica fume were investigated. It was found that the use of polycarboxylate ethers and nano silica improves the ITZ structure between RCA and cement hydration products and promotes the formation of a denser microstructure. The results confirm that nanomodified component F can serve as a valuable resource for low‐carbon cements, and the use of RCA, combine pozzolanic additive, policarboxylate ethers and nanosilica is an effective approach to produce low‐carbon concretes with enhanced durability performance