Using fine recycled concrete aggregates (FRCA) in concrete manufacturing points towards achieving sustainability in recycled aggregate valorisation. The higher absorption and amount of hardened cement paste of FRCA may impair concrete performance. One of the most influenced properties is drying shrinkage; this is because of the extra cement paste content and higher porosity and deformability of FRCA when compared to natural sand. Thus, the influence of FRCA on shrinkage appears to depend on the quality of FRCA and how its absorption is considered during mix design. In this study, the influence of FRCA mineralogy and quality on drying shrinkage is evaluated, also considering the compensation of FRCA absorption rates. In addition, the feasibility of different models to predict the ultimate shrinkage is also analysed. The quality of FRCA and the compensation of water absorption cause different effects on concrete according to the property evaluated. The storage of water inside the FRCA particles causes no influence (or even a beneficial influence) on the shrinkage of concretes. Models used to estimate the drying shrinkage show they are still reliable with the use of FRCA.

Recycled aggregate produced from crushed waste concrete is suitable for use in structural concrete. It reduces the demand for non-renewable resources and also for energy in general. However, RA is more porous than most natural aggregates. The porosity of the concrete cover defines the corrosion resistance of reinforced concrete, and it is therefore disputed how the use of recycled aggregate may affect the durability of reinforced concrete. This paper describes the corrosion-related performance of reinforced concrete with recycled aggregates in the initiation stage (determined by the carbonation and chloride ingress) and propagation stage (determined by the electrical resistivity and cracking) of corrosion. The aspects of interest are not only the porosity of RA but also its effects on the chloride binding, carbonation, electrochemical properties and corrosion cracking development.

The scarcity of fine natural aggregates and the negative environmental impact of their extraction make it necessary to find new sources of aggregates for the construction industry. The use of recycled aggregates (RA) derived from waste concrete crushing is a viable option for reducing non-renewable raw material consumption. The quality of these aggregates is lower than that of natural aggregates. In particular, the water absorption (WA) of the fine fraction of RA is a topic of constant debate due to the limitations of the standardized practices for determining it. Several methods have previously been proposed concerning this. Among these, the electrical conductivity method has the highest potential for effective WA determination. However, the influence of particle size and shape on the measurement remains unknown. In this study, the electrical conductivity method is applied to determine the WA of different particle size ranges in both natural and recycled aggregates. The results show that the paste content is the main variable that influences the WA of RA, whereas the size and shape of particles have no discernible influence on the measurements made using the electrical conductivity method. The present work expands upon previous studies by demonstrating the universality of the method irrespective of the particle size.