The international community since the 30s of last century began to use concrete admixtures. China's 50 years since the last century, and a few started to develop the use of concrete admixtures; the last century, 70 years industry has begun to rise admixture, research team began to grow, production companies increasing continuous research and development of new products, applications continue to expand to expand. After nearly 30 years of efforts, China's additives industry has been considerable development.

First, stable development of synthesis technology to naphthalene-based superplasticizer, new varieties of the rapid development of synthetic superplasticizer

Synthesis of superplasticizer is a concrete admixture of the most important products, can be used alone, but also with other products using the compound; to the end of 2005, there were 2m synthetic superplasticizer enterprises, of which large-scale enterprises nearly 80, an annual output of 1.11 million tons of superplasticizer, the annual sales income of about 5.1 billion, the highest in the world. Among them, naphthalene sulfonate formaldehyde condensate superplasticizer accounted for all the synthesis of superplasticizer production about 80%. My naphthalene superplasticizer mature and stable production processes, products, close to the level of foreign countries, but more than half of enterprises are too small, better performance of the high concentration of superplasticizer (Na2SO4 content of less than 5%) of the dosage is also Less than 5%.

The past five years, China's synthetic superplasticizer product diversification, is the superplasticizer one of the characteristics of technological development. More from the original products to a single amino-naphthalene sulfonate, a new melamine, aliphatic poly carboxylic acid salt, and many other varieties of common development. New production process than the naphthalene superplasticizer Department of simple, low investment, in the performance but also has significant features, better technical and economic benefits can be compared with foreign product quality.

Poly-carboxylate superplasticizer research and production, the development of China's superplasticizer a bright spot. There are independent intellectual property rights of domestic manufacturing enterprises, including Shanghai Architectural Institute of Science and admixture plant, Jiangsu Province Academy of Building Research, China Academy of Building Research, etc., there are 10 enterprises with the production of poly-carboxylate superplasticizer the ability to . Among them, Shanghai Architectural Institute of Science and 7,000 tons of annual production, and applied in a number of key projects. China Poly carboxylate superplasticizer production technology and foreign products are still far from, the key is the basis of foreign chemical manufacturers better, molecular weight distribution and precise, our poly-carboxylate superplasticizer also need to resolve the absorption, anti-foaming and so on.

Second, full range of concrete admixtures, continuously improve product performance

Many kinds of concrete admixtures, it can reduce water consumption on coagulation and improve the strength of concrete superplasticizer to improve the workability of fresh concrete pumping agent, used to adjust the setting time of the retarder on the coagulation and promote coagulation agent, to reduce shrinkage cracking of concrete used in the expanding agent, shrinkage-reducing agent, can improve the performance of freeze-thaw resistance of concrete to extend the service life of coagulation on the air-entraining agents, under the conditions of negative temperature in winter during the construction used in antifreeze, etc. and so on, basically able to meet China's current conditions, the construction of various concrete performance requirements. Some foreign species in the country is almost always present at the national and industry standards has been the product of the admixture of 14 properties were clearly defined.

Concrete construction technology for the upgrading of various additives. In 2005, the annual production of coagulation on the expansive 100 million tons, compared with an annual output in 1999 has quadrupled 250,000 tons of concrete expansion agent also by the high-alkali high-doped (15% -20%), the soda -doped (10% -12%), and gradually to low-alkali low-doped (6% -8%) development.

Quick-setting agent used in sprayed concrete, the main regulator hardening concrete setting time, in 2005 production of approximately 10 million tons. Before quick-setting agent in China and nearly all of the quick-setting agent powder over the past two years, production of alkali-free liquid quick-setting agent has increased significantly, greatly reducing the number of operating surface dust, reducing the strength of sprayed concrete post-loss, increased injection concrete project quality.

Air-entraining agent in pumping agent, antifreeze and other compound additive widely used in 2005, annual output 8000 tons. Traditional rosin soap type air-entraining agents have also been modified to conduct a variety of methods, the new triterpenoid saponin air-entraining agents have several manufacturers.

Through a variety of different functional components of the appropriate compound, can be an integrated high performance composite concrete admixture, while meeting the various requirements of concrete projects. Generally speaking, China's complex admixture of preparation technology and production techniques are constantly improving and enhancing the process.

Third, automated production has just started, the full implementation of large companies began to automate production

Conventional additives in the production process, measurement, temperature control, reaction time control, feeding and other processes are manual, there are often errors and mistakes, ranging from volatility caused by the quality, re-appeared waste. The use of automation and control technology to improve traditional production process is the production technology of concrete admixtures is one important way to improve, but also the production of concrete admixtures business development direction.

At present, the fully automated production line technology, high content, the investment costs are higher, Jiangsu Bote New Materials Co., Ltd., Shandong Province Academy of Building Research, Foshan, Ryan Building Materials Co., Ltd., Zhejiang Wulong Chemical Co., Ltd., and a group of new and rebuilt production line of large enterprises began to try to fully automated production, and achieved good results.

Some manufacturers of synthetic admixture admixtures key technology of automated monitoring, such as Beijing synthesis of a factory on the naphthalene superplasticizer reaction temperature for the entire monitoring, for improving product quality, reduce the quality of fluctuations play an important role.

4, concrete admixture of green production technology needed to strengthen

Like other building materials, concrete admixtures on the production of the green more and more attention. Additive manufacturers are also clearly felt that environmental pressures, taking note of the production area and residential area of separation, the production of pressure vessel safety.

Many manufacturing enterprises in the admixture of green production techniques, carried out the study and application of a variety of ways. Manufacturers pay great attention to the production process to reduce emissions, recycled water utilization. Enterprises should also be strengthened in the future admixture of various raw materials and finished products environmental performance evaluation of the work, a number of complex admixture plants should be retrofitted with dust removal equipment, collecting dust workshop, improving production conditions, to protect the safety of workers.
Sodium Naphthalene Formaldehyde
Melamine Based Plasticizer
Polycarboxylate superplasticizer