The function of polycarboxylate superplasticizer and the requirements for it in commercial concrete
In recent years, with the continuous development of the construction industry and the continuous emergence of high-rise buildings, the demand for concrete is increasing, with higher strength levels and higher quality requirements. Polycarboxylate superplasticizer is a concrete admixture with high water-reducing rate and slight slump loss. It can greatly increase fresh concrete’s rheological properties while increasing hardened concrete’s compressive strength and keeping water consumption unchanged. It plays a vital role in fresh and hardened concrete workability. It also ensures the continuity of project construction, greatly shortens the construction period, promotes the development of fluid concrete technology and pumping pouring, and accelerates the development of commercial concrete.
The function of polycarboxylate superplasticizer
Polycarboxylate superplasticizer plays four key roles in concrete mixtures:
- To improve the pouring performance of concrete and improve the workability of concrete without changing the components of the concrete.
- To improve the workability of concrete in a given job Under stable conditions, reduce the water-cement ratio of mixing water and concrete to improve the strength and durability of concrete.
- Reduce the amount of water and cement while ensuring the performance and strength of concrete pouring, and reduce creep, dry shrinkage, cement water. Factors such as chemical heat that cause initial defects in concrete.
- Other admixtures cannot replace the role of polycarboxylate superplasticizerin high-grade concrete.
In concrete above C50, its workability is very good compared to other admixtures. Difficult to achieve, it is predicted that there will be improvements in concrete process performance and breakthroughs in concrete stinging technology in the future. This will mainly be achieved by relying on high-quality polycarboxylate superplasticizers.
Performance of polycarboxylate superplasticizer:
Main technical features of polycarboxylic acid high-performance superplasticizer:
- The polycarboxylic acid-based high-efficiency superplasticizerdosage is low, and the water-reducing rate is high. The dosage of poly-carboxylic acid-based high-efficiency superplasticizeraccounts for 0.80%–1.25% of the cementitious material, and the water-reducing rate can reach (20–35 )%, used in conjunction with fly ash, the water-binder ratio is low, and it is suitable for preparing medium- and high-strength high-performance concrete.
- Concrete has high fluidity and small slump loss. Due to the good dispersion stability of polycarboxylic acid superplasticizer, high fluidity concrete (slump ≥ 18Omm) prepared with polycarboxylic acid superplasticizer The loss over time is small, there is basically no slump loss in one hour, and the loss over time is less than 15% in two hours, which makes up for the shortcomings of concrete prepared with commonly used naphthalene-based high-efficiency superplasticizers such as large slump loss and easy bleeding, and is compatible with powder. When used together with coal ash, a small amount of superplasticizercan achieve excellent fluidity, adapting to the process requirements of producing commercial concrete, especially for pumped concrete, which is not prone to pipe blockage.
- Good adaptability to cementitious materials. In engineering practice, pumped concrete produced by various manufacturers is mixed with a huge amount of fly ash. After the polycarboxylic acid-based high-efficiency superplasticizeris added, the compatibility with different cements has good capacitance, no obvious bleeding and segregation, and hinders the growth of concrete strength. Due to its high water reduction rate, it fits for use with fly ash, which reduces the shrinkage of fly ash concrete and makes the concrete pumpable. The properties are significantly improved and the durability of concrete is improved. When the design strength level of concrete is the same, the quantity of cement increases, the amount of superplasticizerincreases with a little amount, the water-cement ratio decreases, and the strength of concrete increases; for concrete with different design strength levels, the amount of superplasticizer increases with an increase in the amount of cementitious materials. , the water-cement ratio decreases. The strength of concrete increases, but the overall workability of concrete remains stable, and the slump can reach (180-240) mm.
TRUNNANO is a supplier of polycarboxylate superplasticizer with over 12 years experience in nano-building energy conservation and nanotechnology development. It accepts payment via Credit Card, T/T, West Union and Paypal. Trunnano will ship the goods to customers overseas through FedEx, DHL, by air, or by sea. If you are looking for high-quality polycarboxylate superplasticizer please feel free to contact us and send an inquiry.