Admixture, additive or agent
The use of the different terms ‘admixture’, ‘additive’ and ‘agent’ in relation to concrete production can lead to confusion.
The practical difference between the terms 'admixture' and 'additive' is the time at which the ingredient is added during the mixing process. An admixture is a prepared substance which can be added to concrete for the purposes of achieving or modifying certain properties or characteristics. Admixtures are added to the concrete, in addition to cement, water and aggregate, immediately before or during the mixing process.
The same substance can be referred to as an additive when it is added to cement during the manufacturing process.
The term ‘agent’ can be used to describe a substance that may be used as an additive to cement or an admixture in concrete, such as a binding agent.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Guide to ISO 19650 for Architecture Firms (2026)
A user gives their low down.
A UK training and membership provider for mould remediation professionals.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
Independent NSI and BAFE study exploring how organisations are changing the way they buy fire safety services.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.
Comments
Concrete is a mixture of three ingredients: aggregates, cement and water. Adding concrete admixtures will result in better quality, better performance and it makes the construction last longer.
Admixtures for concrete to be added in low doses (less than 5% of total volume). This should be added at the time of mixing the concrete. They accelerate the hydration of the concrete. The accelerators are of two types, setting accelerator and hardening accelerator. They facilitate the concrete layers by making it more manageable. The water-reducing plasticizers give it better resistance.