Durability of crushed fine recycled aggregate concrete assessed by permeability-related properties

摘要

One of the paths taken towards the greening of concrete has been through the use of recycled aggregates as replacement of their natural counterparts. After decades of studies, the partial use of coarse recycled aggregates is considered acceptable, yet the use of fine recycled aggregates (FRAs) is highly restricted in concrete production. This restriction is based on technical concerns; for example, the presence of FRAs in concrete allegedly hinders its performance beyond acceptance. More recently, several studies seem to point to different conclusions regarding the use of FRAs in concrete: if the materials' specificities are considered during the mixing and composition design of concrete, FRAs may be considered a viable source for concrete production even if, from a durability point of view, they might still present some limitations. This paper presents some results for the durability of FRA concrete by assessing the materials' permeability properties. Different compositions were cast and tested for durability-related properties, such as water absorption by immersion, capillary absorption, carbonation, chloride penetration and electrical resistivity. The results show that the use of FRAs in concrete production is viable, meaning that it is possible to use FRAs in concrete production without neglecting the existing criteria for structural purposes.