Mechanical and Durability Properties of Recycled Aggregate Concrete: Effect of Recycled Aggregate Properties and Content

The use of recycled concrete aggregates as an alternative aggregate material in concrete has been studied over the past two decades. It is now recognized that the recycled aggregate concrete (RAC), where natural aggregates are replaced with recycled concrete aggregates, is a promising technology for conserving natural resources and reducing the environmental impact of concrete. This paper presents a study on mechanical and durability properties of concretes manufactured with recycled aggregates of different sizes and contents. A total of 14 batches of RACs were manufactured. Tests were undertaken to establish the compressive strength, elastic modulus, flexural strength, splitting tensile strength, workability, drying shrinkage, and water absorption of each batch. Test parameters comprised the recycled aggregate replacement ratio, size of coarse aggregates, and mixing method used in the preparation of concrete. The results indicate that the compressive strength is not the only decisive factor on mechanical and durability-related properties of RACs. It is shown that the properties of different RAC mixes of the same compressive strength are affected by the size and content of the coarse aggregates.