Durability and rheological properties of concrete with recycled fine and coarse aggregates and LC3

The use of recycled aggregates (RA), including fine recycled aggregates (FRA) and coarse recycled aggregates (CRA), combined with limestone calcined clay cement (LC3) could be a viable, economical, and eco-friendly route for the minimization of the environmental effects generated by OPC and construction and demolition (C&D). This experimental research study has been carried out by comparing LC3 and CEM I binders mixed with natural aggregates (NA), FRA (incorporation ratio 25 and 50 vol%), and CRA (incorporation ratio 50 and 100 vol %). Different concrete mixes’ mechanical, durability, and long-term rheological properties were studied through compressive strength tests, steady chloride migration to evaluate the chloride ion penetration coefficient, carbonation assessment by accelerated methods, shrinkage, and creep. The experimental results reveal that the LC3-70 binder (70 % clinker and 2:1 of calcined clay to limestone) shows better mechanical properties and improved compressive strength by 11–17 %, depending on the curing age, relative to CEM I with NA. Addi- tionally, it significantly improves the chloride coefficient resistance (by around 71 %) and long-term rheological properties (shrinkage and creep by up to about 50 %), although it negatively affects carbonation resistance. These results demonstrate that LC3-70 is a promising binder for producing concrete with RA, since it exhibits adequate durability and chloride resistance, and long-term rheological properties, particularly when RA, including FRA and CRA, is used as a source of aggregates.