Which aggregate type is most commonly used in concrete mixes?

Natural sand and gravel are the most commonly used aggregate types in concrete mixes due to their availability and suitable properties. These materials are abundant in nature and have the proper size and shape to create a strong bond within the concrete matrix. Natural sand and gravel provide the necessary strength, workability, and durability to the concrete, which is essential for structural applications.

The shape and texture of natural aggregates contribute to the performance of fresh and hardened concrete, allowing for good particle packing and minimizing voids in the mix. This results in a dense concrete structure, which increases its mechanical properties, such as compressive strength and resistance to weathering. Additionally, the relative cost-effectiveness of natural aggregates makes them the preferred choice for a wide range of construction projects.

Other aggregate types, like recycled metal scraps, wood chips and sawdust, or plastic pellets, do not typically offer the same beneficial characteristics required for concrete production and are not widely used in traditional concrete mixes. Recycled materials might be used in specialized applications, but they don't compete with the essential properties provided by natural sand and gravel in conventional concrete formulations.