Polycarboxylate superplasticizer is the third generation of high-performance superplasticizer developed after ordinary plasticizers and superplasticizers. It is the world's most cutting-edge, best application prospects and best overall performance superplasticizer.
Chemical properties of polycarboxylate superplasticizer
FORM: Liquid .
Formaldehyde content : ＜0.05% .
Chloride ion content : ＜0.6% .
Total alkali : ＜0.15% .
Technical Data of concrete mixed with polycarboxylic acid superplasticizer
Water reduction rate: ＞35% Concrete bleeding rate: ＞50% Concrete air content ＜6% 1 day compressive strength ratio of concrete: ＞170% 28 days compressive strength ratio of concrete: ＞130% Difference in setting time (Initial setting to final setting) : -90 to +120 min 28 days concrete shrinkage ratio : ＜110%Polycarboxylate superplasticizer have advantage of low dosage and high water reduction rate.. When the dosage is about 1.0%, the water reduction rate exceeds 35%. Good economic benefits: The overall project cost is lower than using other types of products.
Early strength and high strength, early strength increased by more than 50%, 28-day strength increased by more than 30%, especially suitable for high-volume fly ash concrete. In the range of low dosage of this kind of water reducing agent, the increase in strength is obvious with the increase of dosage.
Low slump loss, the 1h slump retention rate is very good, it remains unchanged at low positive temperature, and the expansion degree increases. If the temperature exceeds 20 degrees, the 1h slump is slightly lost, but it is also maintained at 95% Above, if the temperature exceeds 30 degrees, the 1h slump retention value is still 93%.
Good workability of concrete: even in the case of high slump, the concrete prepared with polycarboxylic acid superplasticizer will not have obvious segregation and bleeding, and the appearance of the concrete is consistent in color. It is extremely beneficial for the preparation of high-fluidity concrete, self-leveling concrete, self-compacting concrete, and fair-faced concrete. When used in the preparation of high-grade concrete, the concrete has good workability, good cohesion, and the concrete is easy to mix.
The concrete mixed with this product has good perforance, in terms of filling, stability, pumpability, strength and compactness, sulfate corrosion resistance, alkali-aggregate reactivity, frost resistance, and shrinkage resistance. The performances such as creep and creep are better than ordinary water reducers.
It has good compatibility with different types of cement and admixtures, and solves the problem of compatibility between other types of water-reducing agents and cementitious materials.
Good product stability: no precipitation and segregation at low temperature
Green and environmentally friendly products, this product has very low alkali content, chloride ion content, sodium sulfate content, and formaldehyde content, and does not pollute the natural environment during the production process. It meets the ISO14000 environmental protection management standard.
The concrete mixed with this product has good perforance, in terms of filling, stability, pumpability, strength and compactness, sulfate corrosion resistance, alkali-aggregate reactivity, frost resistance, and shrinkage resistance. The performances such as creep and creep are better than ordinary water reducers.
1. The mixing amount of Polycarboxylate superplasticizer is 0.4% to 2.5% of the total weight of the gelling material, and the usual mixing amount is 0.8% to 1.5%. Before use, a trial mix test of concrete should be carried out to find the best mixing amount.
2. Polycarboxylic acid water-reducing agent can not be mixed with naphthalene-based superplasticizer. The mixer and mixer truck that have used naphthalene-based superplasticizer must be rinsed before use, otherwise the water-reducing effect may be lost.
3. When using the polycarboxylic acid superplasticizer, it can be directly mixed in the form of the original solution, or it can be formulated into a solution of a certain concentration for use, and the amount of water brought in by the polycarboxylic acid superplasticizer itself is deducted.
4. Because the water reduction rate of concrete mixed with polycarboxylic acid superplasticizer is relatively large, the slump is highly sensitive to the water consumption, and the water consumption must be strictly controlled during use.
5. Polycarboxylic acid superplasticizer has good adaptability to most cements, but for individual cements, the water reduction rate may be low and the slump loss may be large. In addition, the fineness and storage time of cement may also affect the use effect of polycarboxylic acid superplasticizer. At this time, it is recommended to appropriately increase the dosage or compound other retarding components to solve the problem.
6. After mixing with superplasticizer superplasticizer, the air content of concrete increases (generally 2% to 5%), which is beneficial to improve the workability and durability of concrete. If it needs to be used in steam-cured concrete or has other special requirements, it needs to be compounded with other admixtures.
7. Since the dosage of polycarboxylic acid superplasticizer is very small, the water reduction rate is high. The use of polycarboxylic acid superplasticizers to prepare various types of high-performance concretes above C45 can greatly reduce project costs and has significant technical and economic benefits; it is used to prepare concrete below C45, although the cost of polycarboxylic acid superplasticizers On the high side, but the overall cost of concrete can be reduced by increasing the amount of mineral admixtures, which also has certain technical and economic benefits.
Eight types of concrete admixtures based on ASTM C494
Type A: Water-reducing admixtures.
Type B: Retarding admixtures.
Type C: Accelerating admixtures.
Type D: Water-reducing and retarding admixtures.
Type E: Water-reducing and accelerating admixtures.
Type F: Water-reducing, high range admixtures.
Type G: Water-reducing, high range, and retarding admixtures.
Type S: Specific performance admixtures.
1. The polycarboxylic acid-based high-performance water-reducing agent should be counted as an inspection lot per 50t, and if it is less than 50t, it should also be counted as an inspection lot. The sampling volume of each inspection lot shall not be less than the external dose required for 0.2t gelling material. The sampling of each inspection lot shall be fully mixed and divided into two equal parts: one part shall be inspected in accordance with the items and requirements specified in Article 6.3.2 and 6.3.3 of this code. Each inspection lot shall not be inspected. Less than twice; the other one should be sealed and kept for half a year. When in doubt, a comparative test should be carried out.
2. The entry inspection items of polycarboxylic acid series high-performance water reducing agent shall include pH value, density (or fineness), solid content (or moisture content), water reduction rate, and early-strength polycarboxylic acid series high-performance reducing agent. The 1d compressive strength ratio of the water agent should be tested, and the setting time difference of the retarding polycarboxylic acid series high-performance water reducing agent should also be tested.
3. When the polycarboxylic acid-based high-performance water-reducing agent enters the site, the initial or elapsed slump (or expansion) shall be carried out according to the inspection batch of the site using the actual raw materials and mix ratios used in the project and the remaining samples of the previous batch. For the parallel comparison test, the allowable deviation should comply with the relevant regulations of the current national standard "Concrete Quality Control Standard" GB-50164.
1. The polycarboxylic acid series high-performance water reducing agent can be used for plain concrete, reinforced concrete and prestressed concrete.
2. The polycarboxylic acid series high-performance water-reducing agent is suitable for high-strength concrete, self-compacting concrete, pumped concrete, fair-faced concrete, precast concrete and steel tube concrete.
3. The polycarboxylic acid-based high-performance water-reducing agent is suitable for concrete with high volume stability, high durability or high workability requirements.
4. The retarding polycarboxylate high-performance water-reducing agent is suitable for mass concrete, but not suitable for concrete construction with daily minimum temperature below 5℃.
5. Early-strength polycarboxylate high-performance water-reducing agent is suitable for concrete with early-strength requirements or construction in low-temperature seasons, but not suitable for concrete constructed with daily minimum temperature below -5°C, and not suitable for mass concrete.
6. When the air-entraining polycarboxylate high-performance water-reducing agent is used in steam-cured concrete, it should be verified by experiments.
After the cement is added with water, due to the molecular cohesion between cement particles and other factors, a flocculation structure will be formed. The water-reducing agent molecule is composed of a hydrophilic group and a hydrophobic group. When the water-reducing agent is added to the cement paste, the hydrophobic group points to the cement particles and adsorbs on the surface of the cement particles to form an adsorption film to make the cement particles With the same charge, under the action of electrostatic repulsion, the flocculation structure is disintegrated and becomes a smaller structure; its hydrophilic group points to the solution. When the cement particles are close to each other, the water-reducing agent molecules on the surface of the cement particles are hydrophilic Repulsive force (called steric hindrance repulsion) is also generated between the groups, which makes the structure more dispersed.
When the flocculation structure is destroyed, the encapsulated water is also released and participates in the flow, which enhances fluidity; in addition, because the hydrophilic groups of the water-reducing agent are very polar, the water-reducing agent adsorption film on the surface of the cement particles can interact with water molecules. A stable volume hydration film is formed, which can play a very good lubricating effect and further enhance the fluidity.
*Microscopic molecular chemistry determines the macroscopic functional effect of water reducing agent.
China Leading Polycarboxylate Superplasticizer Supplier
Zhengzhou, Henan, China