What is anything added to concrete mix other than water, sand, cement, and aggregate considered?

In the context of concrete production, anything added to the concrete mix beyond the standard components of water, sand, cement, and aggregate is referred to as an additive. Additives are substances used to modify the properties of the concrete, improve its performance, or enhance specific characteristics. They can serve various purposes, such as accelerating or retarding the curing process, improving workability, reducing water content, or increasing durability.

Additives can include chemical admixtures like plasticizers, superplasticizers, retarders, and accelerators, among others. They are crucial in adapting concrete to specific environmental conditions or project requirements. The term "add mixture" does not accurately represent the nature of these components, as it could lead to confusion with the full mix itself. Therefore, labeling these substances as additives correctly conveys their role in the concrete formulation.