Chemical Admixtures - Cement
Superplasticizers, also known as plasticizers or high-range water reducers (HRWR), reduce water content by 12 to 30 percent and can be added to concrete with a low-to-normal slump and water-cement ratio to make high-slump flowing concrete.
Superplasticizer
Plasticizers are chemical compounds that enable the production of concrete with approximately 15% less water content. Superplasticizers allow reduction in water content by 30% or more. These additives are employed at the level of a few weight percent. Plasticizers and superplasticizers retard the curing of concrete. [1]
Use of Water Reducers, Retarders, and Superplasticizer
The use of superplasticizers may produce high strength concrete (compressive strength up to 22,000 psi). Superplasticizers can also be utilized in producing flowing concrete used in a heavy reinforced structure with inaccessible areas. Requirement for producing flowing concrete is defined in ASTM C 1017.
Superplasticizer: Types, Advantages & Disadvantages
1. Superplasticizers reduces the water content. 2. It reduces the cement content. 3. Also, increases the workability of concrete. 4. It reduces the permeability of concrete. 5. They are easy to placement. 6. Increased long terms. 7. It develops the early strength. Disadvantages of Superplasticizer: 1.
Plasticizers For Concrete - Principle, Types & Advantages
Plasticizers have plasticizing action due to the presence of polymer molecules present in it. These molecules when mixed with concrete absorbs on the surface of the cement grains that would create a ionic group that points outwards. This would finally give a negative charge to the cement particles. Action of Plasticizers On Concrete
- Why are plasticizers used in concrete?
- Chemical substances called plasticizers, sometimes referred to as water reducers, are mixed into concrete to increase workability without weakening it. They aid in lowering the water content of the mixture, which is necessary to preserve the appropriate strength of the concrete.
- How do plasticizers and water reducers affect concrete strength?
- Since the heat of hydration of mass concrete goes down when the cement weight goes down, plasticizers can do this. Plasticizers and water reducers are chemical admixtures used to make concrete more workable. Unless the mixture is “starved” of water, increasing the w/c ratio reduces the concrete’s strength.
- How do plasticizers work?
- Plasticizers allow concrete to be poured and molded more easily during construction while reducing cracking as it cures. They also improve the tensile strength of concrete. Plasticizers work by embedding themselves between chains of polymers, spacing them apart. This helps the concrete and plastics become more flexible and malleable.
- How do Plasticizers make concrete stronger and last longer?
- Plasticizers make concrete stronger and last longer by reducing the amount of water and cement needed to reach a certain level of workability. Since the heat of hydration of mass concrete goes down when the cement weight goes down, plasticizers can do this. Plasticizers and water reducers are chemical admixtures used to make concrete more workable.
- What is a plasticizer used for?
- Plasticizers are commonly used with polyvinyl chloride (PVC) and concretes. Plasticizers serve several crucial purposes in civil engineering materials: Workability – Plasticizers allow concrete to flow more easily into molds and around rebar during pouring. They make the concrete more malleable and improve slump. This makes large pours easier.
- Should you add plasticizers to concrete and PVC?
- Adding plasticizers to concrete and PVC comes with a mix of pros and cons: Advantages: Disadvantages: Here are some key points about plasticizers in concrete: Plasticizers are chemical admixtures that increase the workability and plasticity of concrete. This makes concrete easier to place and finish.
