section_path: Composition/Admixtures
section_name: Admixtures
paragraph_text: Admixtures
  
  Admixtures are materials in the form of powder or fluids that are added to the concrete to give it certain characteristics not obtainable with plain concrete mixes. Admixtures are defined as additions "made as the concrete mix is being prepared". The most common admixtures are retarders and accelerators. In normal use, admixture dosages are less than 5% by mass of cement and are added to the concrete at the time of batching/mixing. (See § Production below.) The common types of admixtures are as follows: