Superplasticizers, which also go by the name of HRWR, which stands for High-Range Water Reducer or plasticizers, are designed to lower the content of water that has been added to a concrete mixture between 12% to 30% with a normal-to-low water-cement and slump ratio to produce high-slump flowing concrete.
Concrete that is flowing is highly-fluid yet the concrete is workable and can usually be placed or poured with no or very little compaction or vibration. The effects of products such as sodium naphthalene sulfonate superplasticizer will only last for between thirty to sixty minutes which typically depends on the dosage rate along with the brand, which results in rapid workability loss. Since loss in slump occurs relatively quickly, naphthalene sulfonate superplasticizer is typically added to the concrete at a job site.
The main aim of adding a product like naphthalene sulfonate superplasticizer to concrete will be to lower the need to add water to the mixture. When the water amount in a concrete mixture is reduced, it allows builders to achieve a much higher-density paste (cement), which will also improve or enhance the overall quality relating to the paste. SNF-A offers the highest reduction rate when compared to the 3 types of superplasticizers for concrete, which stands at an average rate of 26%.
When it comes to SNF-B and SNF-C, the water reduction rates are 25% for SNF-B and 23% for SNF-C. So it becomes clear that the type of sodium naphthalene sulfonate that offers the highest water reduction rates will be a superior quality product within the construction sector, and also an option that is more expensive.
Even though the physical characteristics of SNF-A, SNF-B, and SNF-C are exactly the same, sodium naphthalene sulfonate prices for each type will differ according to the chemical composition.
Net starch-fluidity is also an important factor when deciding on the overall quality of “sodium naphthalene sulfonate”. The starch present in SNF will influence many characteristics of concrete in a positive way such as compressive strength, creep, and heat-of-hydration. The SNF-A offers the highest net starch-fluidity which stands at 250mm.
– NA2SO4 Concentration
The curing environment “standard” in construction sectors uses different NA2SO4 concentrations. The NA2SO4 solution is what suppresses the hydration rate of a cement mixture. As the NA2SO4 concentration present in sodium naphthalenesulfonate starts to increase, the compressive strength and dynamic-elastic nature of the concrete start to decrease.
This means that premium quality naphthalene sulfonate superplasticizer is going to feature a lower NA2SO4 concentration. For instance, SNF-A currently possesses the lowest NA2SO4 concentration which is equal to or less than 5%. SNF-C, on the other hand, has a NA2SO4 concentration that is the highest, standing at 18%. While SNF-B has a NA2SO4 concentration of around 10%.
In conclusion, the naphthalene sulfonate superplasticizer is one of the valuable chemical compounds in the construction and building sector. It plays an important role in reducing water requirements while helping to strengthen concrete mixtures. However, it is recommended to conduct a bit of research when it comes to choosing the best quality naphthalene sulfonates according to the needs and requirements of the project.