What is Polynaphthalene sulfonate?
Sodium Polynaphthalene Sulfonate (PNS) is an anionic surfactant, emulsion stabilizer, dispersant and suspending agent with a pH range between 7 – 9. This anionic surfactant is hydrotropic meaning it has the ability to enhance the water solubility of another surfactant.
What is naphtha based admixture?
Product Description. Naphtha Formaldehyde Based Admixture is a high range, low dosage, super plasticising admixture for slump retention. It is a product based on refined Naphthalene formaldehyde blends.
What are retarders in concrete?
Retarding admixtures, which slow the setting rate of concrete, are used to counteract the accelerating effect of hot weather on concrete setting. Retarders keep concrete workable during placement and delay the initial set of concrete. Most retarders also function as water reducers and may entrain some air in concrete.
Why steel is used in RCC?
This reinforced concrete can handle both tension and compression. Steel is 100 times more tensile than concrete so that it can handle tensile forces. Although steel has 15 times more compressive strength than concrete, that makes structure expensive hence role in tackling compressive force is played by concrete.
How is concrete admixture calculated?
Calculation of Sand & Coarse Aggregate Quantities: Admixture = 1.2 % by weight of cement = 5.064 kg.
Why is admixture used in concrete?
Admixtures are used in concrete to enhance the performance of the mix in various ways. Generally added before or during the mixing process, admixtures can increase the strength the mix, accelerate or slow down the curing process among other benefits.
What is accelerator MCQs?
This set of Concrete Technology Multiple Choice Questions & Answers (MCQs) focuses on “Accelerators and Retarders”. Explanation: An admixture used to speed up the initial set of concrete is called accelerator. 2.
What is sodium polynaphthalene sulfonate used for in concrete?
The use of sodium polynaphthalene sulfonate in the production of flowing concrete can reduce the water-cement ratio, then the strength of the concrete material can be hardened. In addition, it is also a raw material for many additives in the construction industry.
What is poly naphthalene sulfonate powder?
Poly Naphthalene Sulfonate (PNS), also called SNF superplasticizer, is a high-range water reducing agent. It is also called naphthalene sulfonate superplasticizer. The primary use of PNS is to produce admixtures for ready-mixed concrete. PNS powder is for the preparation of dry mortar.
What is the water reduction rate of sodium naphthalene sulfonate?
The water reduction rate of sodium naphthalene sulfonate is as high as 25% or more. It can effectively increase the fluidity of concrete, reduce bleeding, and segregation. So it can improve the workability of concrete, facilitating construction, and being easy to compact.
What are the advantages of SNF cement?
Its high purity feature makes cement particles with high low foaming, high range water reducing and strengthening. In addition, it also improves cement mobility and workability. SNF is easily soluble in ethylene glycol, diethylene glycol, glycerol, and water, slightly soluble in alcohols, but it is insoluble in organic solvents.