A plasticiser is a substance or material added to concrete to make it softer, improve workability and strength, and reduce water requirements. Plasticisers are available in two forms: mineral admixtures, like fly ash, and chemical admixtures, like Superplasticisers.
The purpose of using plasticisers is to enhance the quality of the cement mixture and make it suitable for construction. It helps:
- Reduce the water-to-cement ratio without hindering workability.
- Prevent shrinkage and cracks in concrete.
- Increase setting time, allowing operators to transport concrete over long distances.
Types of Plasticisers
Mineral Admixtures / Plasticisers
Mineral admixtures are substances added to concrete mixtures to improve the properties of the concrete. The most common types are cementitious admixtures, which exhibit cementing properties, such as ground granulated blast furnace slag.
The second type is pozzolanic admixtures, which, when mixed with calcium hydroxide, show cementitious properties. They are usually added to Portland cement mixture to enhance the long-term strength and reduce the cost of concrete. These include fly ash, metakaolin, and silica fume.
Chemical Admixtures
The purpose of chemical admixtures is to change the properties of concrete in a particular way. Like mineral admixtures, chemical admixtures come in different forms. The most common type is water-reducing admixtures or plasticisers.
These admixtures help attain a higher strength by reducing the water-cement ratio while achieving the same workability by decreasing the cement content, which helps decrease the heat of hydration in mass concrete. They can reduce the water content by more than five per cent but less than twelve per cent. Examples of chemical admixtures include retarders, water reducers, accelerators, and air-entraining agents.
Also known as high-range water reducers, superplasticisers are one of the most recent and effective types of chemical admixtures. They offer several benefits, including increased fluidity through flowing, self-compacting concrete, penetration, and self-levelling. They also help reduce water to cement ratio by providing high strength, reducing shrinkage, and enhancing durability by eliminating water to decrease diffusion and permeability.
Benefits of Plasticisers in Concrete
- Improve the strength of concrete, making it ideal for various applications.
- Improve workability to allow concrete to be placed more easily and smoothly, which can help cut labour requirements.
- Enhance the permeability of concrete and help reduce water absorption, vapour transmission, and thermal cracking.
- By reducing water content, plasticisers can help achieve greater durability and, as a result, increase the durability of the concrete.
- Reduce the amount of shrinkage in concrete to reduce the chances of cracking and increase the quality of the concrete.
Contact Us to Learn More
At Bisley Biz, we offer a wide range of construction products and materials, including plasticisers. Our materials are made with high precision to meet our customers’ unique needs and the various industry standards. We can also provide technical support to ensure you get the best experience throughout your project execution. Contact us online or call us at 612-8905-4200 for inquiries.
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