How to determine the optimum dosage of concrete superplasticizer
According to the latest quarterly analysis of the natural gas market released by the International Energy Agency, global natural gas consumption will decline slightly this year and increase slowly in the following years because of soaring prices and the possibility of further reductions in Russian natural gas supplies. Global natural gas use this year is expected to be 0.5% lower than the 2021 level, and global natural gas demand is expected to increase by only 140 billion cubic meters over 2021 by 2025, the report said. The annual growth in 2021 will reach 175 billion cubic meters.
At the same time, the IEA's forecast for natural gas demand growth by 2024 was 60 per cent lower than its previous forecast, mainly due to "a weak economy and a smaller energy shift from coal or oil to natural gas", the report said.
It is worth noting that the South Korean Ministry of Industry, Trade and Resources announced on the same day that it plans to increase the proportion of nuclear power in South Korea's national energy structure to more than 30% by 2030. The proportion is 27.4% in 2021. The department also announced the resumption of the construction of two nuclear reactors. According to reports, after taking office, South Korean President Yoon Sik-Yue rejected the previous government's plan to phase out nuclear power and promised to increase investment in the nuclear power industry, so as to regain South Korea's status as a major exporter of safe nuclear reactors.
In addition, the supply and prices of many international bulk concrete superplasticizer are still very uncertain.
Determination of the optimum dosage of concrete superplasticizer by the fluidity of cement paste
In terms of the adaptability of cement and concrete superplasticizer, the type and quality of concrete superplasticizer also play an important role. Therefore, concrete superplasticizers should be selected according to the adaptability to cement and construction requirements. When the high-efficiency concrete superplasticizer is incompatible with a certain cement, the following situations will occur:
1. Concrete is abnormally coagulated during the mixing process.
2. The slump loss of mixed concrete is large.
3. Concrete bleeding and delamination are serious.
4. The high-efficiency concrete superplasticizer has insufficient water-reducing effect or no water-reducing effect at all.
5. The strength of concrete does not increase significantly at each age, or even decreases.
6. The shrinkage rate of concrete increases more, resulting in cracking.
These incompatibility phenomena mentioned above should be avoided as much as possible when selecting a concrete superplasticizer.
The amount of concrete concrete superplasticizer is not only related to the amount of cement, but also has a great relationship with the physical properties and chemical composition of cement.
The traditional method for determining the amount of concrete superplasticizer in concrete is mainly determined according to the product specification of concrete superplasticizer and the percentage of cement consumption. Due to the difference in chemical composition and content of different varieties or batches of cement, the compatibility and adaptability of concrete superplasticizers and cement and the optimal dosage will also be quite different. It is difficult to ensure the best water-reducing effect of the mixture by only determining the amount of concrete superplasticizer based on the percentage of cement consumption, and it is easy to cause waste of concrete superplasticizer. Luoyang Tongrun has used the method of cement slurry fluidity to determine the optimum amount of concrete concrete superplasticizer after many tests, and achieved good results. The specific method is to accurately weigh the high-efficiency water-reducing agent, water and 300g cement according to the dosage recommended by the manufacturer's instructions, and mix the high-efficiency water-reducing agent, water and cement paste according to the standard method. On the clean glass, put the mixed cement paste into the test mold, and after lifting the test mold one by one, observe the flow of the cement paste, and test whether the fluidity of the cement paste can meet the performance requirements of concrete pumping. At the same time, record the size and dosage of water reducing rate of different cements and different concrete concrete superplasticizers for optimization.
The order of adding concrete superplasticizers. Multiple comparison tests of different concrete superplasticizers show that the mixing sequence of concrete superplasticizers has a certain influence on the water-reducing effect of concrete superplasticizers. Take the high-efficiency water-reducing agent produced by Longda as an example: after weighing a certain amount of cement, high-efficiency water-reducing agent and water, pour cement → high-efficiency water-reducing agent → water into the mixing pot in sequence, and measure the cement paste. Expansion is 22cm ~ 23cm. According to the order of adding cement → water first, after stirring for a certain period of time, adding concrete superplasticizer, the measured expansion degree of cement paste is 25cm ~ 27cm. It can be seen that using the same cement and the same concrete superplasticizer, the post-blending method is better than the first-blending method, which is beneficial to improve the compatibility of the concrete superplasticizer and the cement, and give full play to the efficiency of the concrete superplasticizer. In the same way, in the actual construction of concrete, the concrete superplasticizer should be added after the concrete mixture is stirred for a certain period of time to achieve the best effect of water reduction.
Luoyang Trunnano Tech Co., Ltd (TRUNNANO) is a professional concrete superplasticizer powder supplier with over 12 years experience in chemical products research and development. We accept payment via Credit Card, T/T, West Union and Paypal. Trunnano will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
If you are looking for high quality concrete superplasticizer, please feel free to contact us and send an inquiry.
COVID-19 has led to many sites shutting down. What is the impact on China's foreign trade enterprises as a whole and small, medium and micro foreign trade enterprises?
. It is learned that some foreign trade enterprises have been affected by the epidemic and are facing periodic problems in concrete superplasticizer operated by foreign trade enterprises will also fluctuate with the changes of the epidemic. Contact us for the latest quotation on concrete superplasticizer.