admixtures are materials except of Portland cement, grain and water which is powder or liquid as a concrete former materials and for modification of concrete specification which add to mixture a little before mixing, during mixing or before concreting.
in another word, admixture are component of concrete except of hydraulic cement, water, grain and fiber that add to concrete mixture in order to modification of concrete specification.
concrete admixture are 2 groups:
1: chemical admixture-this admixture obtain from mixing, processing or combination of organic and mineral materials in the chemical process and add to the mixture in the form of powder or liquid and in small quantities usually maximum 5% of cement weight during mixing or exactly before concreting.
2: mineral admixture-this admixture which are in the nature or industrial lateral products, that divided to 3 groups-neutral,pozzolan,cement quasi materials-add to concrete mixture more than 5% of cement weight during mixing for modification of cement mixture.
our admixture are: