What is the primary function of fine aggregate in a mixture?

The primary function of fine aggregate in a mixture is to fill the voids between larger aggregates, which enhances the overall cohesiveness of the concrete mix. Fine aggregates, typically consisting of sand or crushed stone, work by occupying the spaces that exist between the larger pebbles or gravel in the mixture. This process not only helps in creating a more dense and stable material but also reduces the amount of required cement, as the space occupied by the fine aggregate means less void space for the cement paste to fill. The improved cohesiveness leads to better workability, making it easier to handle and shape the concrete during application.

While fine aggregates also play a role in aesthetic aspects and overall weight of the concrete mix, their main purpose is to create a better particle arrangement and increase stability, which directly contributes to the performance and durability of the final product.