Compatibility of polycarboxylate superplasticizer with other admixtures.
PCE water reducing polycarboxylate superplasticizer
Polycarboxylic Acid Water Reducer is a powerful water reducer and cement dispersant in cement concrete applications. It is widely used on roads, bridges, dikes, tunnels, skyscrapers and other projects.
The water-reducing agent is environmentally friendly, non-flammable, explosive and can be transported safely in trains and cars.
Depending on the difference in body structure, polycarboxylic acid superplasticizer products can be divided into two categories: one type uses acrylic acid or methacrylic acid as the backbone and grafts polyethers with different side chain lengths.
The others are polyethers whose main bond is maleic anhydride and which have different side chain lengths. Based on this, several high-performance water-reducing products with different properties have been derived.
Prior to the formation of polycarboxylic acid mixtures, there were mixtures of lignosulfonate, naphthalenesulfonate-formaldehyde condensate, melamine-formaldehyde condensate, acetone sulfonate-formaldehyde condensate, formaldehyde sulfate condensate, and so on.
The new generation of polycarboxylate superplasticizers overcomes some of the disadvantages of traditional superplasticizers. It has the advantage of low dosing, good droplet retention, low concrete shrinkage, high molecular structure control and high potential for high performance. Significant advantages, such as the absence of formaldehyde in the process.
For the synthesis of a water-reducing agent of a polycarboxylic acid, the design of the molecular structure is very important, including the backbone group, the side chain density, and the side chain length in the molecule. The synthetic methods mainly include an in situ polymerization grafting method, first a polymerization method, then a functionalization method and a direct monomer copolymerization method.
In many concrete projects, traditional high-performance concretes, such as the naphthalene series, are increasingly unable to meet project needs due to technical performance constraints.
A new generation water-reducing agent that has attracted a lot of attention at home and abroad, polycarboxylic acid, a high-performance water-reducing agent because it actually designed an efficient molecular structure based on a dispersed cement mechanism, is dispersed in the supertype and can prevent concrete formation.
Recession loss without causing obvious deceleration, it can have a higher softening effect with low quality, good fluidity retention, high freedom of cement to adapt to many molecular structures, multiple synthesis techniques and large space for high performance, which can improve concrete Impact is significant, it can reduce concrete shrinkage, harmful substances has a very low and other technical performance properties that give the concrete excellent workability, good strength development, excellent durability and high performance polyacid-based water-reducing agent.
Arboxylic has good technical performance advantages and the environmental protection properties meet the needs of modern concrete technology. Thus, high performance dewatering agents based on polycarboxylic acids are gradually becoming a preferred blend for the production of high performance concretes.
According to reports, the use of polycarboxylic acid additives accounted for more than 80% of all high-performance additive products in Japan, and more than 50% in North America and Europe. In my country, polycarboxylate water-reducing agents have only been used successfully in the Three Gorges Dam, the Sutong Bridge, the Tianwan Nuclear Power Plant, the Beijing-Shanghai High-Speed Train, and other large national water protection systems, bridges, and nuclear power plants. and rail projects with significant results.
Polycarboxylic acid high-efficiency water reducing agent is characterized by low dosage and high water reducing rate.