Due to the extensive use of industrial by-products and waste materials in the cement production process, the adaptability of admixtures has become increasingly prominent. This requires the development of different types of admixtures for different gelling materials. For example, polycarboxylic acid admixtures, according to market demand, will develop varieties that meet various requirements by changing the branching method, and facilitate engineering use and quality control. Admixtures for the development of high-strength, anti-aging At present, the strength of concrete is continuously increasing, and admixtures play a significant role in improving the performance of concrete. In the future, it is necessary to continuously develop admixtures for high-strength ultra-high-strength concrete.
Concrete additive is an admixture added during concrete mixing. It is mainly used to improve the performance of concrete. From the point of addition ratio of admixture, it is generally not more than 5%. Although it contains a small amount, it has played an active role in improving the performance of concrete and has become an indispensable part of the current development of concrete. The additives used in concrete mainly refer to different types of water reducing agents. The extensive promotion of concrete admixtures has led to significant improvements in the strength of the concrete, its brittleness and its own weight, and has improved the applicability of concrete construction. For example, adding antifreeze to concrete can make concrete construction work in the cold winter. The use of superplasticizers enables the renewal of concrete placement and flow regimes.
Concrete admixtures are called admixtures. In the process of disposing and mixing concrete, it is necessary to add some products according to the city design requirements and test results to enhance or change the performance of concrete. This part of the added substances is called admixture, plus The use of the agent should be strictly controlled, and the total amount required should be 5% by weight of the regional cement. Admixture quality, type selection, dosage and ratio have a significant impact on the quality and performance of concrete. In the actual construction process, concrete processing, addition and use of admixtures should be carried out in strict accordance with the relevant standards set by the State.
For all kinds of concrete admixtures, the role of the precipitant is mainly to reduce water consumption, increase the density and elasticity of the concrete, and make the concrete durable. The air entraining agent can improve the solubility of the concrete, and reduce the internal crack of the concrete by improving the internal structure of the concrete, so that the concrete can improve its antifreeze and impermeability. For concrete with higher frost resistance requirements, it is possible to properly perform bleed air or a mixture of precipitation additives. For concrete with higher impermeability requirements, the density of concrete must be increased by high-performance precipitants. At the same time, the air entraining additive is used to reduce the occurrence of water seepage and improve the impermeability of the building structure.
Cement is a very basic material in the construction industry and plays a very important role in the development of the national economy. However, in the cement production process, the energy consumption is high and the utilization rate is low, mainly due to the accumulation of fine powder particles during the grinding process, which causes the paste ball and the adhesive liner to reduce the grinding efficiency, so that about 80% to 90 % of the energy is consumed in the form of heat. In order to improve this situation, it is common in the industry to add a small amount of grinding aid to the grinding material to improve the grinding effect. Rate and reduce the energy consumption of grinding.
Triethanolamine is an important fine chemical product and a commonly used raw material for cement grinding aids and concrete admixture manufacturers. Triethanolamine (TEA) can form a water-soluble chelate with cations in cement hydration system, and forms many melting points on the surface of cement particles, which increases the dissolution rate of C3A and C4AF, resulting in faster reaction with gypsum. The increased amount of calcium sulphoaluminate is beneficial for coagulation and compaction, thereby increasing early strength. At the same time, due to the formation of unstable complexes in the hydration process of cement, the degree of supersaturation of Ca(OH)2 is increased, which can effectively prevent the formation of loose crystalline products in the early stage of C3A hydration, thereby improving the compactness of cement stone and strength.
Concrete additive is an admixture added during concrete mixing. It is mainly used to improve the performance of concrete. From the point of addition ratio of admixture, generally not more than 5%. For all kinds of concrete admixtures, the role of the precipitant is mainly to reduce the water consumption, increase the density and elasticity of the concrete, and make the concrete durable. The air entraining agent can improve the solubility of the concrete, and reduce the internal crack of the concrete by improving the internal structure of the concrete, so that the concrete can improve its antifreeze and impermeability. For concrete with high frost resistance requirements, it is possible to properly perform bleed air or a mixture of precipitation additives.
Concrete admixtures shall be selected carefully as per the specifications and shall be used as recommended by the manufacturer or by lab testing report. The quantity of admixtures to be used for specific application of admixtures are recommended by the manufacturers. For use in large construction projects, the quantity of the admixture to be used shall be obtained from tests reports for concrete mixed with admixtures at various percentage admixtures use. These tests are conducted to understand the behaviour of admixtures on the desired quality and strength of concrete at different quantity of admixtures used. Thus, the optimum quantity of admixtures can be selected for specific application based on results.