Polycarboxylic acid water reducer is a high-performance water reducer and a cement dispersant in the application of cement concrete. It is widely used in highways, bridges, dams, tunnels, high-rise buildings and other projects.
The product is environmentally friendly, non-flammable, non-explosive, and can be safely transported by trains and cars.
In many concrete projects, traditional high-efficiency concretes such as naphthalene series are increasingly unable to meet the needs of the project due to the limitations of technical performance.
A new generation of water-reducing agent that has attracted much attention at home and abroad, polycarboxylic acid-based high-performance water-reducing agent, because it has truly designed an effective molecular structure based on the mechanism of dispersed cement, it has a super-dispersed type and can prevent concrete slump loss Without causing obvious retardation, it can play a higher plasticizing effect at low content, has good fluidity retention, the cement has a large degree of freedom in adapting to a wide range of molecular structures, has many synthesis techniques, and has a large room for high performance.
The effect is remarkable, it can reduce the shrinkage of concrete, and the content of harmful substances is very low. It gives the concrete excellent construction workability, good strength development, excellent durability, and the polycarboxylic acid-based high-performance water reducing agent has good Comprehensive 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 first-choice admixture for formulating high-performance concrete.
According to reports, the use of polycarboxylic acid admixtures in Japan has accounted for more than 80% of all high-performance admixture products, and North America and Europe have also accounted for more than 50%. In my country, polycarboxylate water-reducing agents have been successfully applied only in the Three Gorges Dam, Sutong Bridge, Tianwan Nuclear Power Station, Beijing-Shanghai High-speed Railway and other large-scale water conservancy, bridge, nuclear power, and railway projects, and have achieved remarkable results.
At the same time, polycarboxylic acid water reducer also has some problems: 1. Insufficient slump retention under high temperature environment; 2. High temperature sensitivity, the same kind of polycarboxylic acid water reducer is constructed in different seasons, and concrete slump retention is far different; 3. Few functional products, it is difficult to meet the requirements of ultra-high, ultra-long-distance concrete pumping, negative temperature construction, ultra-early-strength concrete preparation and high durability of concrete; Compared with concrete, the viscosity of concrete is higher than that of concrete, which is not conducive to construction; 5. It is highly sensitive to the mud content of sand and gravel aggregates. 6. The adaptation to machine-made sand is also poor, and the mixing amount is sensitive to affect the construction.