Polycarboxylic Acid Water Reducer is a high performance water reducer and cement dispersant in cement concrete application. It is widely used in roads, bridges, dams, tunnels, skyscrapers and other projects.
Water reducing agent is environmentally friendly, non-flammable, non-explosive and can be safely transported in trains and cars.
According to the difference in backbone structure, polycarboxylic acid superplasticizer products can be divided into two categories: one type uses acrylic acid or methacrylic acid as backbone and grafts polyethers with different side chain lengths. The others are polyethers with maleic anhydride as the main bond and different side chain lengths. Based on this, several high performance water reducing products with different characteristics were derived.
Before the advent of polycarboxylic acid mixtures, there were mixtures of lignosulfonate, naphthalene sulfonate formaldehyde condensate, melamine formaldehyde condensate, acetone sulfonate formaldehyde condensate, formaldehyde sulfate condensate, etc. The new generation of polycarboxylate superplasticizers overcomes some of the disadvantages of traditional superplasticizers. It has the advantages of low dosage, good drop retention performance, low concrete shrinkage, high adjustability in molecular structure, and high potential for high performance. Notable advantages, such as not using formaldehyde in the process.
For the synthesis of polycarboxylic acid water reducing agent, the design of the molecular structure is very important, including the main chain group, the side chain density and the length of the side chain in the molecule. Synthesis methods mainly include in situ polymerization graft method, first polymerization and then functionalization method and direct monomer copolymerization method.
In many concrete projects, traditional high-efficiency concretes such as the naphthalene series are increasingly unable to meet the project’s needs due to technical performance limitations. A new generation of water reducing agent that has attracted a lot of attention at home and abroad, the polycarboxylic acid-based high-performance water reducing agent, because it really designed an effective molecular structure based on the dispersed cement mechanism, has a super-dispersed type and can prevent loss of slump of concrete Without causing obvious delay, can exert greater plasticizing effect with low content, good fluidity retention, a large degree of freedom for cement to conform to a wide range of molecular structures, multiple synthesis technologies and a large space for high performance, which can improve the concrete The effect is remarkable, it can reduce the shrinkage of the concrete, the content of harmful substances is very low and other technical performance characteristics, which give the concrete with excellent workability, good strength development, excellent durability and the high-performance polyc acid-based Water reducing agent. Arboxylic has a good Comprehensiv Technical performance advantages and environmental protection characteristics meet the needs of modern concrete engineering. Therefore, polycarboxylic acid-based high-performance water reducing agents are gradually becoming the preferred mixture for preparing high-performance concrete. According to reports, the use of polycarboxylic acid additives in Japan accounted for more than 80% of all high-performance additive products, and in North America and Europe it also accounted for more than 50%. In my country, polycarboxylate water reducing agents have been successfully applied only in Three Gorges Dam, Sutong Bridge, Tianwan Nuclear Power Plant, Beijing-Shanghai High Speed Railway and other national large-scale water conservation systems, bridges, nuclear power and rail projects, with remarkable results.