Naphthalene series superplasticizer is a non air entraining superplasticizer synthesized by chemical industry. Chemical name naphthalene sulfonate formaldehyde condensate, it has strong dispersion effect on cement particles.
Naphthalene system is used to prepare large fluidized concrete with cast-in-place concrete and prefabricated components requiring early strength and high strength. It can improve and improve all kinds of properties of concrete. It is widely used in highways, bridges, dams, ports, tunnels, electric power, water conservancy and civil engineering, steam curing and natural curing prefabricated components.
At present, the sodium sulfate content in the market is divided into high consistency and low consistency.
Below are indicators of low concentration:
main technical indicators:
1. Appearance: powder yellow brown powder
2, solid content: powder is more than 94%, liquid is more than 40%.
3. Pulp fluidity is more than 230mm.
4, the content of sodium sulfate is less than 10.
5, chloride content is less than 0.5%.
1, when the concrete strength and slump are basically the same, the cement dosage can be reduced by 10-25%.
2. When the water cement ratio is constant, the initial slump of the concrete will be increased by more than 10cm, and the water reduction rate can reach 15-25%.
3, the concrete has a significant early strength and enhancement effect, its intensity increased by 20-60%.
4, improve the workability of concrete and comprehensively improve the physical and mechanical properties of concrete.
5. Good adaptability to all kinds of cement and good compatibility with other types of concrete admixtures.
6. It is especially suitable for use in the following concrete projects: fluidized concrete, plasticized concrete, steam cured concrete, impermeable concrete, waterproof concrete, natural cured precast concrete, steel bar and prestressing reinforced concrete, high strength and ultra-high strength concrete.
7, the concrete slump loss is large, and the slump loss is nearly 40% in half an hour.
matters needing attention:
1. When porous aggregate is used, water should be added before adding water.
2, when the slump is large, it should be noted that the vibration time is not too long to prevent bleeding and stratification.
Naphthalene series superplasticizers can be divided into high concentration products (Na2SO4 content < 3%), medium concentration products (Na2SO4 content 3%-10%) and low concentration products (Na2SO4 content > 10%) according to the content of Na2SO4 in their products. At present, most synthetic plants of naphthalene series superplasticizers have the ability to control Na2SO4 content below 3%, and some advanced enterprises can even control Na2SO4 content below 0.4%.
Naphthalene series superplasticizer is the most widely used high-efficiency superplasticizer (accounting for more than 70% of the dosage of superplasticizer) with high water reduction rate (15%-25%), no air entrainment, little influence on setting time, relatively good adaptability to cement, and can be used in combination with other additives at relatively low prices. . Naphthalene superplasticizer is often used to prepare large fluidity, high strength and high performance concrete. The concrete slump loss of naphthalene superplasticizer is faster. In addition, the adaptability of naphthalene superplasticizer to some cement needs to be improved.