Polycarboxylate superplasticizer 10

In the 1930s, it was found that after mixing sulfite pulp waste into concrete, the workability of the mix could be improved, and the strength and durability could also be improved. In 1935, E. W. Scripture in the United States first developed a water-reducing agent with linosulfonate as the main component, and obtained a patent in 1937. In the 1950s, it was widely used in the United States slip form concrete, dam concrete and winter construction concrete. In 1962, Hattori Ken, first of all, of the Japanese Kawang alkali Company, first developed a water reducer with R mononaphthalene sulfonate formaldehyde condensation sodium salt as the main component, referred to as naphthalene series water reducer. This type of water reducer has the characteristics of high water reduction rate, and is suitable for preparing high strength (compressive strength up to 100MPa) or slump up to 20 (2) concrete. Subsequently, in 1964, the Federal Germany successfully studied sulfonated melamine formaldehyde resin superplasticizers, which also had the characteristics of high water reduction rate, good early strength effect and low gas intake with naphthalene series superplasticizers. At the same time, it had good adaptability to steamed concrete products and cement products with high content of aluminate (mainly C3A), and could prepare high-strength or high-fluidity concrete. Germany thus invented the fluid concrete, so that concrete from the original manual pouring or hanging pot pouring development to pumping construction, saving manpower, improve efficiency, ensure quality, eliminate noise, so that the technical level of concrete and construction level has a great leap.
Due to the important contribution of high efficiency water reducing agent to concrete modification, its application has become the third major breakthrough in the history of concrete development after reinforced concrete and prestressed concrete. Marked by the development and application of high efficiency water reducing agent, concrete technology has entered the third generation from plasticity, dry hardening to fluidization.
In the early 1990s, the United States first proposed the concept of high performance concrete (HPC), that is, the concrete is required to have high strength, high fluidity, high durability and other properties, high performance concrete put forward higher requirements for water reducer, requiring high performance water reducer with high water reduction rate, large flow and slump loss. Some new superplasticizers have been rapidly developed and applied, such as polycarboxylic acid series, sulfamic acid series superplasticizers.