Concrete additives

Concrete additives are powder or liquid additives (" additives ") that influence certain properties of the concrete . They may only be added to the concrete if they do not impair the hardening of the cement , the strength and durability of the concrete or the corrosion protection of the reinforcement . In contrast to concrete admixtures , they have to be taken into account as volume components when creating the concrete recipe. The aggregate (previously "aggregate") is not counted among the concrete additives .

If concrete additives are to be used, the composition of the concrete must be determined in advance with suitability tests, as prescribed, for example, in DIN 1045.

Mineral fines

• Rock flour
• Pozzolanic substances :
  • Fly ash , mostly from coal combustion, less often from lignite combustion
  • Tuff , trass
  • Silica fume

Organic substance

• Synthetic resins in the form of dispersions ("synthetic resin dispersions") to improve processability and adhesion

More fabrics

• Color pigments for coloring the concrete
• Steel, glass or plastic fibers for fiber concrete

Web links

• Cement information sheet for concrete technology: Concrete additives - admixtures and additives (PDF file; 184 kB)

Individual evidence

1. ↑ Entry on concrete additives. In: Römpp Online . Georg Thieme Verlag, accessed on July 11, 2014.