1. In the early 1990s, the United States first proposed the concept of high performance concrete (HPC), which is a successful example of the combination of new superplasticizers and concrete materials science.
2. In 1824, British I. Aspdin obtained the Portland cement patent, and cement concrete was widely used.
3. In 1962, Japan Hattori Kenichi first used naphthalenesulfonic acid formaldehyde condensate (n≈10) as a concrete dispersant, and in 1964, Japan Kao Shiji Company sold it as a product.
4. In 1963, the Federal Republic of Germany successfully developed the melamine sulfonate formaldehyde condensate.
5. In 1966, Japan first applied high-strength concrete and began to produce prestressed concrete piles.
6. From 1971 to 1973, Germany first succeeded in developing fluid concrete with superplasticizer, and the vertical pumping height of concrete reached 310m.
7. The development direction is the research of HPC and the use of composite superplasticizers (CSP) to realize the full calculation method design of HPC mix ratio and CSP formula design.
Direction of development
1. Superplasticizer: modification of naphthalene and melamine superplasticizers, polyacrylate superplasticizer, polyacrylic acid graft copolymer superplasticizer, sulfamate superplasticizer, sulfonation Ketone-aldehyde condensation polymer, lignosulfonate high-efficiency, industrial waste production superplasticizer.
2. Compound admixtures: low-alkali and low-volume liquid compound admixtures, compound superplasticizer and its formulation design, low-alkali and low-volume liquid compound antifreeze, micro-expansion multifunctional waterproofing agent, liquid expansion agent, liquid quick-setting Agent, super retarder.
3. Other additives: shrinkage reducing agent, alkali aggregate reaction inhibitor, surface hardener, high-efficiency mold release agent
Admixtures are the fifth component of concrete. Adding admixtures can improve the workability of concrete and increase the strength and durability of concrete. The characteristics of concrete admixtures are many varieties and small dosages, which have a greater impact on the performance of concrete. Therefore, its variety selection, application technology and quality control are more important than other concrete components.