Assessing the Mechanical Properties and Frost Resistance of Recycled Coarse Aggregate Concrete in Finland

Recycled concrete coarse aggregates (RCCA) offer a sustainable alternative to virgin aggregates in concrete production, addressing both environmental and economic concerns. This study evaluates the mechanical properties and freeze-thaw resistance of concrete with 50% and 100% RCCA replacement percentages, using aggregates sourced from demolished structures in Finland. A total of eleven concrete mixes were tested, categorized into four groups based on testing objectives: mechanical strength, elastic properties, creep and shrinkage, as well as freeze-thaw resistance. The results show that compressive strength decreased with higher RCCA replacement, but the extent of the reduction varied across mixes and testing ages. At 100% RCCA, the strength reduction was more noticeable, but it still varied depending on the mix. Young’s modulus declined with increasing RCCA content, while creep strain increased, particularly at 100% RCCA replacement. In contrast, freeze-thaw resistance remained comparable to the control, with minimal internal damage and low surface scaling. These findings underscore the feasibility of RCCA in concrete applications, highlighting both its potential and performance limitations.