Construction companies or contractors as well as concrete producers are often faced with the headache of improving the performance of concrete and when they take up large government or national projects, improving the performance of concrete becomes more stringent and must be considered as the most cost-effective way to improve the performance of the concrete to meet the demand.
Before the emergence of polycarboxylic acid admixtures, there are lignosulfonate admixtures, naphthalene sulfonate formaldehyde condensate, melamine formaldehyde condensate, acetone sulfonate formaldehyde condensate, aminosulfonate formaldehyde condensate, etc.
In the early 1980s, Japan took the lead in the successful development of Polycarboxylate Superplasticizer.
The new generation of polycarboxylic acid high efficient water reducing agent overcomes some of the disadvantages of traditional water reducing agents, with low dosage, good slump-proof performance, low shrinkage of concrete, strong adjustability of molecular structure, high performance potential, and no formaldehyde is used in the production process and other outstanding advantages.
Table of Contents
- What are polycarboxylate superplasticisers?
- Product advantages of polycarboxylate superplasticisers
- Application trends of polycarboxylate superplasticisers
What are polycarboxylate superplasticisers?
Polycarboxylate Superplasticizer is a high-performance water reducing agent and a cement dispersant used in cement concrete. It is an organic compound mainly composed of polycarboxylic acid groups and side chains attached to them.
The main action of Polycarboxylate Superplasticizer is to reduce the adsorption and surface tension between water and cement particles by reacting with the water-cement ratio in concrete.
This mechanism of action, known as dispersion, results in a reduction of friction between concrete particles, which improves the fluidity, plasticity and workability of the concrete.
Product advantages of polycarboxylate superplasticisers
- Good compatibility with all kinds of cement, good slump keeping performance of concrete, prolong the construction time of concrete.
- Low mixing amount, high water reduction rate, small shrinkage.
- Improve the early and late strength of concrete greatly.
- The product has low chloride ion content and low alkali content, which is beneficial to the durability of concrete.
- The production process of this product is pollution-free and does not contain formaldehyde, which is in line with the international standard of ISO14000 environmental protection management, and is a green product.
- Using polycarboxylate water reducing agent, more slag or fly ash can be used to replace cement, so as to reduce the cost.
Application trends of polycarboxylate superplasticisers
In many concrete projects, naphthalene system and other traditional high-efficiency concrete can not meet the needs of the project more and more due to the limitations of technical performance.
The new generation of water reducing agent, polycarboxylic acid high-performance water reducing agent, which has attracted much attention at home and abroad, has a super-dispersed type, which can prevent the loss of concrete slump without causing obvious retardation, and can play a higher plasticising effect under low dosage, with good fluidity retention, wide adaptability to cement, large degree of freedom in molecular structure, many synthetic techniques, great scope of high performance, significant enhancement effect on concrete, reduction of concrete shrinkage, low harmful substance content and other technical performances.
There is a lot of space, significant enhancement effect on concrete, can reduce the shrinkage of concrete, the content of harmful substances is very low and other technical performance characteristics, endowed with excellent construction and ease of concrete, good strength development, excellent durability, polycarboxylic acid high-performance water reducing agent has a good comprehensive technical performance advantages and environmental protection features, in line with the needs of modern concrete engineering.
Therefore, polycarboxylic acid-based high-performance water reducing agent is gradually becoming the preferred admixture for formulating high-performance concrete. It is reported that the use of polycarboxylic acid admixture has accounted for more than 80% of the total amount of all high-performance admixture products in Japan, and more than 50% in North America and Europe.
In China, polycarboxylic acid water reducing agent has been successfully applied only in the Three Gorges Dam, Sutong Bridge, Tianwan Nuclear Power Station, Beijing-Shanghai High-speed Railway and other national large-scale water conservancy, bridge, nuclear power and railway projects, and has achieved remarkable results.