In the modern construction industry, there are numerous types of additives used with concrete. These are either in the chemical or mineral forms and are meant to enhance specific properties of the concrete mixture used in construction.
More specifically, chemical super plasticizing admixtures, such as set-controllers and water-reducers are mostly used to improve the intrinsic properties of hardened and fresh concrete.
Any chemical compound which is added to concrete admixture to enhance the properties of concrete in the hardened or fresh state is known as “chemical admixture”. It is defined as a material apart from water, hydraulic cement, fiber reinforcement, or aggregates, that is used as ingredient of mortar or concrete, and is added to the concrete mix immediately before or during the mixing process.
Super plasticizing admixtures are ranked as one of the most widely used concrete admixtures in modern building projects. In this blog, you will find all you need to know about super plasticizer admixtures, such as what it is and how it works.
What are the Types of Admixtures?
There are various types of admixtures mixed with concrete. Some chemical admixtures, known as “water reducers”, are used to reduce the water content required when mixing concrete to enhance workability. Similarly, “air entrainers” are chemical admixtures that trap air bubbles in the concrete and provide it resistance to frequent freeze and thaw cycles in cold climates.
In the same way, “accelerators” and “retarders” are admixtures that control the duration of hardening of concrete mixes and the rate of strength gain.
Besides these, there are several special purpose chemical admixtures used in the construction industry. Viscosity modifying agents are used to control the viscosity of the concrete, shrinkage reducing chemicals help prevent concrete shrinkage, while corrosion inhibiting admixtures help to prevent concrete from corroding.
However, before using any super plasticizing admixtures it is important to know its compatibility with the varied types of concrete mixes used in the construction industry.
It is recommended to follow the instructions provided by leading super plasticizing admixture manufacturers, such as Sakshi Chem Sciences, to know compatibility between concrete mixes and super plasticizer admixtures.
What are Super Plasticizing Admixtures?
Super plasticizer admixtures are water reducing chemical compounds that are useful to enhance the workability of concrete. Increasing the water to cement ratio in concrete tends to enhance its overall strength unless the concrete mix is deprived of water.
Increasing the durability of concrete is easier by using super plasticizers without the need to wait for excessive water to evaporate in a concrete mix.
Adding super plasticizers, plasticizers, water reducers or dispersants in concrete makes it more manageable and takes less time for mixing too.
Super plasticizers are usually used with pozzolanic ash mixed with cement to make concrete. This concrete mix is normally required for making fiber-reinforced or high-strength concrete. According to construction experts, you only need to add around 1-2% by weight of super plasticizer to the cement to get the desired reduction in water content.
However, care should be taken to avoid using too much super plasticizer as it can affect the functions of some chemicals in the construction mix.
How do Super Plasticizing Admixtures affect Concrete?
Super plasticizing admixtures have polymer molecules that make concrete more flexible. When the polymer molecules are added to concrete, they stick to the outside of the cement grains and create an ionic group which mainly grows outward. The cement crystals thereby gain a negative charge, and they expel each other, which results in breaking the blocks of particles.
Besides the negative charge of the cement grains and their repelling effect, they are also surrounded by a film of water molecules that keeps the grains separated sufficiently. This is what makes the concrete mix smoother, more fluid and easier to work with.
Related Post: How to Choose the Right Superplasticizer for Your Concrete?
What are the Types of Super Plasticizing Admixtures?
There are mainly two types of super plasticizers –
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Hydrophobic Super Plasticizers
This type of super plasticizer allows a significant amount of air to enter the concrete mix. It helps to make the concrete more flexible by lowering the tension of water in the concrete solution.
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Hydrophilic Super Plasticizers
This type of super plasticizer is mainly used to improve the concrete’s fluidity and plastic properties.
What are Super Plasticizing Admixtures Used for?
Below is a list of purposes that super plasticizers are normally used for –
- Super plasticizers help to add air into the concrete mix to make it more fluid
- Super plasticizer compounds reduce the total amount of water required for making concrete
- Super plasticizing agents help to enhance the strength of the concrete mix
- Super plasticizer chemicals make the workability of concrete more effective and versatile
What are the Benefits of Super Plasticizing Admixtures?
There are numerous advantages and benefits of using super plasticizers, such as –
- Enhancing the fluidity of concrete without increasing its water to cement ratio
- Improving the strength of the concrete without the need to add excess quantity of cement
- Enhancing the compressive strength of concrete mix by 25%
- Allows compacting the concrete surface without the need for vibrating
- Increasing the adhesion of concrete to make it more workable
- Helping to create high density concrete more efficiently
- Reducing the quantity of water required in a concrete mix
- Making concrete resistant to cracks and damage from low temperatures
Conclusion
A super plasticizing admixture is a type of additive mixed with cement to improve the concrete’s durability, performance, and workability. These admixtures are useful to make concrete more fluid, which makes it easier to work for different purposes. It also helps to enhance the strength of concrete while reducing its permeability once it gets hard.
There are various types of super plasticizers that are mixed with concrete. For instance, water reducing and retarding plasticizers are among the most common types of super plasticizers used in the modern construction industry. Water reducing super plasticizers, as the name suggests, allow you to use less water to make strong concrete.
Super plasticizing admixtures are mainly helpful to enhance the workability of concrete, without the need to increase water content, and make it easier to be used for versatile uses. Retarding super plasticizers tend to slow the hardening time of the concrete, which is highly useful for construction projects in extremely hot and dry climates.
Construction experts recommend that to get the most benefits of super plasticizer admixtures, it is necessary to buy from renowned and reliable super plasticizer manufacturers, such as Sakshi Chem Sciences. Follow us on Facebook here.