When：
When properties cannot be made by varying the composition of basic material.
To produce desired effects more economically.
Unlikely to make a poor concrete better.
Not a substitute for good concrete practice.
Required dose must be carefully determined and administered
How：
Check job specification
Use the correct admixture
Never use one from an unmarked container.
Keep containers closed to avoid accidental contamination.
Add the correct dosage.
Avoid adding ‘a little bit extra
Use a dispenser
Wash thoroughly at the end the day
Best if added to the mixing water
Manufacturer’s recommended dosage is usually adequate
Trial mixes are important to determine most effective dosage
