Concrete Admixtures

Concrete admixtures refer to some materials added before or during the mixing process of concrete to improve the performance of new mixed concrete or hardened concrete. These admixtures are added to concrete in small amounts, usually no more than 5% of the mass of cement, to significantly improve the workability, strength, durability or adjust the setting time of concrete. At the same time, the use of concrete admixtures also helps save cement, improve construction efficiency, and meet different engineering needs.

In concrete engineering, the rational use of admixtures can significantly improve engineering quality, reduce costs and meet different engineering needs. Therefore, when selecting and applying concrete admixtures, the appropriate type of concrete admixture should be selected according to the characteristics and requirements of the project to ensure the best engineering effect.

Different Types of Concrete Admixtures For Sale

As a leading concrete admixtures manufacturer and supplier in China, Kingsun concrete admixtures for sale mainly include Sodium Gluconate 98% min, Sodium Naphthalene Sulfonate(SNF/PNS/FND), Polycarboxylate Superplasticizer(PCE), Sodium Lignosulfonate, Calcium Lignosulfonate. Although they all belong to the popular construction chemicals, they have different functions and uses in construction industry. Please view the detailed introduction of these products.

(1) Sodium Gluconate in Concrete

Sodium gluconate is widely used in concrete. It is generally used as a concrete water reducing admixture and retarder, and has a significant improvement on the performance of concrete. By reasonably controlling the amount of sodium gluconate added, the quality and performance of concrete can be significantly improved, thereby achieving better construction and use effects.

1. Used as a water reducer

As a water reducer, sodium gluconate can significantly reduce the water-cement ratio (W/C) of concrete, thereby improving the strength and durability of concrete. When the water-cement ratio remains unchanged, the addition of sodium gluconate can also improve the workability of concrete and act as a plasticizer.

• Improve strength. When the cement content remains unchanged, the addition of sodium gluconate can reduce the water content in concrete, thereby improving the strength of concrete. For example, when the addition amount of sodium gluconate is 0.1%, the amount of water added can be reduced by 10%.
• Improve workability. When the addition amount of sodium gluconate is below 0.1%, the degree of improvement in workability is proportional to the addition amount.

2. Used as a concrete retarder

As a concrete retarder, sodium gluconate can significantly delay the setting time of concrete, allowing the concrete to maintain plasticity and workability for a longer period of time. This feature is particularly important in hot weather or in concrete projects that need to be placed for a long time.

• Extending the setting time. When the dosage of sodium gluconate is less than 0.15%, the logarithm of the initial setting time is proportional to the amount added, that is, if the amount added is doubled, the initial setting time is delayed to ten times.
• Improving construction performance. Delaying the setting time can avoid the formation of joints on the structure and enhance the structural strength. At the same time, it is also beneficial to the construction and pouring of concrete, especially in pumped concrete, high-flow concrete, large-volume concrete and high-strength performance concrete. The application of sodium gluconate can significantly improve construction efficiency and quality.

In addition to being a water reducer and retarder, sodium gluconate can also have the following effects on concrete:

• Improve fluidity. By reducing the cohesion and surface tension of cement colloid, sodium gluconate can improve the fluidity of concrete, making it easier to construct and pour.
• Reduce cracks. Sodium gluconate can reduce the pores inside the concrete and shorten the setting time, thereby improving the surface quality of the concrete, reducing shrinkage cracks and cracking of the concrete, and improving the durability and crack resistance of the concrete.

(2) Sodium Lignosulfonate in Concrete

Sodium lignosulfonate is mainly used as a water reducer, which has a significant effect on improving the performance of concrete. It has been widely used in various types of construction projects. For example, in the production of high-strength concrete products such as large-volume concrete, prefabricated components, and bridges, the use of sodium lignin sulfonate can significantly improve the strength and durability of concrete, while reducing production costs and environmental pollution.

Main performance advantages

• Water-reducing performance. Sodium lignin sulfonate can significantly reduce the water-cement ratio of concrete, improve the fluidity of concrete, and make concrete easier to construct and pour. The water reduction rate is high, usually up to 9%~11%, which helps save water resources and cement consumption.
• Enhance concrete strength. The product can react with calcium ions in cement hydration products to form a highly adhesive network structure, thereby improving the strength and durability of concrete. At the appropriate dosage, it can significantly improve the early strength and long-term strength of concrete.
• Improve concrete workability. It can improve the workability of concrete, making it more uniform, easy to mix and pour. This helps to improve the construction efficiency and quality of concrete.
• Retarding effect. Sodium lignosulfonate has a retarding effect, which can delay the initial and final setting time of concrete. Especially in hot seasons, this feature helps to avoid too fast coagulation of concrete and provide a longer working window for construction. However, it should be noted that in low temperature environments, the retarding effect may prolong the construction period, so it is necessary to appropriately adjust the dosage or choose other types of water reducers.
• Environmental protection and economy. Sodium lignosulfonate is a modified product of natural polymers with the advantages of low cost and environmental friendliness. Its use helps to reduce environmental pollution and energy consumption in the concrete production process.

(3) Calcium Lignosulfonate in Concrete

Calcium lignosulfonate in concrete has many advantages, such as water reduction, strengthening, improving workability, slowing down setting, environmental protection and economic benefits. Therefore, the rational use of calcium lignin sulfonate in concrete engineering is of great significance to ensure engineering quality and construction efficiency.

• Water-reducing performance. As a surfactant, calcium lignosulfonate can significantly reduce the water consumption of concrete. Through its hydrophobic group, it is directional adsorbed on the surface of cement particles, so that the cement particles are negatively charged and repel each other and disperse, thereby releasing free water to achieve the purpose of water reduction. This characteristic can greatly reduce the water consumption and improve the working performance and strength of concrete while maintaining the same slump of concrete.
• Improve the strength of concrete. Adding calcium lignin sulfonate can also significantly improve the strength of concrete. It improves the pore structure of cement, slows down the crystal growth rate, and makes the crystal growth more sufficient, so that more fibrous crystals are interlaced with each other to form a strong network structure. This structure significantly improves the compressive strength, impermeability and durability of concrete.
• Improve workability. When the cement dosage and water consumption of concrete remain unchanged, the slump of low-plasticity concrete can be increased by about two times, and the early strength is basically close to that of unadmixed concrete. This makes the concrete more uniform and smooth during mixing and pouring, reduces the bleeding and segregation of concrete, and improves the density and strength of concrete.
• Retarding effect. This product has a significant retarding effect and can delay the hydration reaction process of cement. It adsorbs on the surface of cement particles to form a protective film, which hinders the direct contact between cement and water molecules, thereby slowing down the hydration rate of cement. This retarding effect allows concrete to maintain its plasticity and fluidity for a long time, which is beneficial to the construction and pouring of concrete. At the same time, by adjusting the dosage of calcium lignin sulfonate, the initial and final setting time of concrete can be accurately controlled to meet the needs under different construction conditions.
• Environmental protection. As a natural polymer compound, calcium lignosulfonate is derived from a by-product of the papermaking industry, so its production and use process has little impact on the environment. At the same time, it does not contain harmful substances such as chloride salts, has no rust damage to steel bars, and meets the requirements of green building materials.
• Economic benefits. The product can also bring significant economic benefits. By reducing water consumption and saving cement consumption, the production cost of concrete can be greatly reduced. At the same time, due to its excellent water-reducing, reinforcing and retarding properties, it can improve the working performance and engineering quality of concrete, thereby reducing waste and rework in construction and further improving economic benefits.

(4) SNF Superplasticizer for Concrete

As one of the most commonly used concrete admixtures, SNF superplasticizer can significantly improve the quality of concrete, including strength, durability and workability. It is especially suitable for various types of concrete projects, including ordinary concrete, high-strength concrete, prestressed concrete, etc. The main models are SNF-A, SNF-B, SNF-C.

Main performance of SNF superplasticizer

• High water reduction rate. The water reduction rate of SNF superplasticizer is usually between 12% and 25%, which means that the water consumption can be greatly reduced while keeping the strength and workability of concrete unchanged.
• Enhanced performance. High-efficiency SNF superplasticizer can significantly improve the compressive strength, flexural strength and static elastic modulus of concrete, making concrete more durable.
• Improve workability. By reducing the surface tension of water, SNF high-efficiency water reducer can significantly improve the workability of concrete, making concrete easier to mix, pour and compact.
• Durability. The use of SNF superplasticizer can also improve the impermeability, freeze-thaw resistance and sulfate erosion resistance of concrete, thereby extending the service life of concrete.
• Improve construction efficiency. Since SNF superplasticizer can significantly improve the workability of concrete, it makes concrete easier to construct and pour, thereby improving construction efficiency.
• Improve concrete quality. It can significantly improve the quality of concrete, including strength, durability and workability.
• Save costs. By reducing water and cement consumption, SNF superplasticizer can save a lot of water resources and raw materials, reducing production costs.

(5) PCE Superplasticizer for Concrete

As a kind of high-efficiency water reducer, PCE superplasticizer can significantly reduce the water consumption of concrete while maintaining or improving the strength and working performance of concrete. It has good compatibility with a variety of cements, so PCE can be widely used in different types of concrete projects, such as bridges, tunnels, high-rise buildings, water conservancy projects, etc.

Performance Advantages

• Improve concrete performance. PCE superplasticizer can significantly improve the workability of concrete, improve the fluidity, plasticity and self-leveling ability of concrete. This makes concrete easier to mix, pour and compact during construction, reducing the difficulty and time of construction.
• Enhance concrete strength. This superplasticizer can significantly improve the performance indicators of concrete such as compressive strength, flexural strength and durability by optimizing the hydration process of concrete. This increase in strength makes concrete more stable and reliable when bearing loads, improving the safety and service life of engineering structures.
• Save water resources and raw materials. Because PCE high-efficiency water reducer has a high water reduction rate, it can greatly reduce the water consumption of concrete, thereby saving water resources. At the same time, due to the use of water reducer, the amount of admixtures (such as fly ash, slag powder, etc.) in concrete can also be reduced accordingly, further saving the cost of raw materials.
• Adapt to complex construction environments. When the high-performance concrete mixing station is far away from the specific project site, PCE high-efficiency water reducer can ensure that the concrete maintains good working properties such as fluidity, slump and expansion during long-term transportation. In addition, for pumping construction, PCE high-efficiency water reducer can reduce the pumping resistance of concrete and improve pumping efficiency.
• Improve concrete microstructure. High-efficiency PCE superplasticizer can disperse cement particles and prevent the rapid formation of cement flocculation structure, thereby improving the microstructure of concrete. This makes the concrete more dense and uniform, and improves the concrete’s impermeability, freeze-thaw resistance and sulfate erosion resistance.
• Environmentally friendly and pollution-free. The product is environmentally friendly and pollution-free during production and use, and meets the requirements of green building materials. This helps promote the sustainable development of the construction industry and reduce the impact on the environment.
• Significant economic benefits. The use of PCE superplasticizer can bring significant economic benefits. Due to the use of water reducer, the water consumption of concrete is reduced, and the amount of cement and admixtures is also reduced accordingly, thereby reducing production costs. At the same time, due to the improvement of concrete performance, the safety and service life of the engineering structure are improved, and the cost of maintenance and replacement is reduced.

Main functions of concrete additives

The functions of concrete admixtures are mainly reflected in improving the performance, workability, strength, durability and working performance of concrete to meet the requirements of different projects for concrete performance. However, when using admixtures, it is also necessary to select and proportion them according to the specific situation and project requirements to ensure their effectiveness and safety.

• Improve the construction performance of concrete. By reducing the amount of water used in concrete, or increasing the fluidity of concrete without increasing the amount of water used, concrete is made easier to construct and pump.
• Adjust the setting time. According to the needs of the project, admixtures can adjust the setting time of concrete, so as to better control the construction progress and the performance of concrete.
• Enhance the strength and durability of concrete. By improving the early and late strength of concrete, increasing its frost resistance, impermeability, abrasion resistance and corrosion resistance, the durability and safety of concrete structures can be improved.
• Control the deformation and cracking of concrete. By reducing the shrinkage and water segregation of concrete, delaying the initial hydration heat, and reducing the temperature rise rate of large-volume concrete, the occurrence of cracks can be reduced and the volume stability of concrete can be improved.
• Improve the working performance of concrete. Some special admixtures, such as fly ash admixtures, can also improve the working performance of concrete and reduce the thermal and dry shrinkage deformation of concrete.