1. General

1.1 Definition

An admixture is a product added in very small quantities to concrete, mortar or grout, before or during mixing. The dose is less than 5% of the cement weight.

The aim is to improve certain properties of concrete, whether in the fresh state during setting and hardening, or in the hardened state.

Additives are covered by the standard NF EN 934 Part 2 (Admixtures for concrete, mortar and grout. Definition – requirements – compliance – marking and labeling).

Each admixture, even if it has several secondary actions, is defined by its main function: the major modification(s) made to concrete, such as the fresh and/or hardened...