What is a potential drawback of using recycled aggregates in concrete mixes?

Using recycled aggregates in concrete mixes can indeed present challenges related to inconsistent quality and properties. This variability often arises due to the source materials used in the recycling process. Recycled aggregates can come from various structures, each with distinct concrete compositions, additives, and curing histories, leading to differences in strength, porosity, and durability.

This inconsistency may affect the performance of the resulting concrete, impacting factors such as workability, setting time, and long-term strength. Engineers and contractors must carefully evaluate and test the properties of recycled aggregates before use to ensure that they meet the required standards for specific applications. Therefore, while recycled aggregates can be a sustainable option, their quality must be thoroughly assessed to maintain the integrity of the concrete mix.