Do you know the origin, development and application of concrete admixtures?

The overall development of concrete admixtures is upward and continues to expand rapidly. However, in production and engineering applications, some technicians still have some problems with concrete admixtures and their application technology. Most concrete admixtures are added before or during the mixing process of concrete, and some are added during the construction process. The total amount added in the additional mixing process is generally no more than 5% of the total mass of the concrete. On the premise of ensuring the basic performance of the concrete, the performance of the additional product is appropriately changed. With the technological development of concrete admixtures and their continuous application in projects, concrete technology has been greatly improved, creating convenient conditions for the use of various high-performance concretes, and easing some of the original engineering difficulties. The future development of concrete admixture technology is directly related to the development of concrete construction technology. Therefore, it is necessary to discuss the current application status and future development of concrete admixtures.

Concrete admixtures have been used as products in concrete for nearly a hundred years. But dating back to ancient times, humans have actually known to use some additives in cementitious materials for construction. Some scholars have verified that in the construction of the Colosseum, people at that time already knew that some cow blood, butter, and milk were used in gel materials such as volcanic ash to improve performance. There are historical records in ancient my country. When Qin Shihuang built the Great Wall, clay, lime, etc. were also used as gel materials, and glutinous rice juice, pig blood, tofu juice, etc. were used to increase its viscosity. These can also be regarded as admixtures. Verifiable information also records that in 1885 Europeans already knew about adding hardening regulators, such as lime and gypsum, to concrete. The use of calcium chloride was popular at the end of the 19th century and is still used today. By 1895, water-increasing agents and plasticizers had been used and mixed into the concrete for road paving, effectively improving the durability of the concrete.

Formal industrial products first appeared in 1910. When the United States developed North America in the 1930s, concrete pavements were quickly frozen due to the severe cold climate. In order to improve the quality of pavement concrete, “Wensha” was used resin” to improve the durability of concrete. The real scientific research product is the “Pozzolitn” water-reducing agent (Pozzolitn), which was successfully researched and manufactured in 1935 by E.W. Scxiptrt of MasterBuilder in the United States, with lignosulfonate in pulp waste liquid as the main component. In 1937, the United States issued the first water-reducing agent patent in history. In 1954, the first batch of concrete admixture inspection standards were formulated.

The official use of concrete admixtures in my country was in the 1950s. At that time, the rosin saponified air-entraining agent developed by experts from the former Soviet Union was introduced and applied in Tianjin Tanggu New Port, Wuhan Yangtze River Bridge and Foziling Reservoir, and achieved great results. achieved a certain effect. Later, concrete plasticizers based on pulp waste liquid from sulfite papermaking and waste honey from the sugar industry were used. At the same time, early strength agents such as calcium chloride, sodium chloride, and triacetate amine were also used. This is where the use of admixtures started.

The development and application of concrete admixtures are of long-term significance. Vigorously developing and promoting the application of concrete admixtures is an important way to promote scientific progress in the construction industry. With the improvement of scientific research and technical capabilities, the variety of concrete admixtures will continue to be developed and increased, the quality will gradually improve, the scope of application and usage will gradually increase, and admixtures will play a greater role and good benefits in the construction industry.

During the construction process of construction projects, the use of admixtures can effectively improve the construction environment, facilitate the use of various mechanical equipment, reduce the workload of relevant construction personnel, and ensure the quality of the project. In addition, It can also successfully complete construction tasks in some harsh environments. Concrete admixtures can significantly shorten the maintenance time after construction, thereby speeding up the demolition of project formwork, enabling faster turnover of formwork, and significantly speeding up the subsequent steel bar tensioning and shearing, thus shortening the entire project period. Greatly shortened. At the same time, the addition of concrete admixtures can also effectively improve the overall quality of concrete projects and improve its strength, durability, frost resistance, and impermeability. In addition, it can significantly improve the drying shrinkage of concrete and the flow properties before solidification. If concrete admixtures are used correctly in construction projects, usually admixtures will not have any impact on the quality of concrete construction, and It can also greatly reduce the use of cement and various auxiliary materials under the premise of scientific use. The reduction in the use of cement-based auxiliary materials not only saves social resources, but also saves the construction cost of the process, and has a positive impact on the following steps. Tamping and smoothing processes provide convenience. Therefore, during the construction process of construction projects, the rational use of concrete admixtures can not only effectively improve the quality of the project, but also enable construction to be carried out from a more economical and reasonable perspective, making the construction of the project twice the result with half the effort.

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