What role does aggregate play in concrete?

Aggregate plays a crucial role in concrete by serving as a filler that provides compressive strength and volume. In concrete mixtures, aggregates make up a significant portion of the volume, typically around 60% to 80%. By including aggregates, the overall density of the concrete is increased, which directly contributes to its compressive strength. The type, size, and grading of the aggregates can significantly influence the concrete's mechanical properties, workability, and durability.

Furthermore, aggregates help to reduce the amount of cement needed in a concrete mix, lowering costs and the environmental impact associated with cement production. In addition to strength and volume, aggregates can affect the thermal performance of concrete, but their primary function is to fill space and enhance mechanical properties.

While aggregates can contribute to the aesthetic aspects of concrete due to their variety in colors and textures, their primary function goes beyond aesthetics. Their role is fundamentally structural, focusing on strength, volume, and stability within the concrete matrix.