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How to buy and use concrete admixture correctly?

Release time:

2022-11-02

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Concrete is widely used in civil engineering and construction. Concrete admixture is a kind of decorative material, which is characterized by impermeability, small dosage, large function and wide application. The admixture greatly improves the performance of ordinary concrete, makes concrete more widely used, and has good social and economic value. More importantly, with the development of science and technology, people's vision is also improving, which requires concrete admixture has better performance and more complete function.

the basic role of concrete admixture:(1) In the case of not reducing the unit water consumption, keep the water-binder ratio unchanged to improve the workability and fluidity of fresh concrete; because the contact area between cement particles and water is greatly increased, the cement is fully hydrated, although the water-binder ratio remains unchanged, but the strength of concrete is often improved to a certain extent. (2) Under a certain degree of work, reduce water consumption, reduce water-binder ratio, and improve concrete strength. (3) Under the condition of maintaining a certain strength, reduce the amount of gelding material, reduce water consumption, keep the water-glue ratio unchanged, save cement and other gelding materials.

Proper purchase and use of concrete admixture can produce huge economic and technical value. It can not only improve the strength of concrete, but also reduce the cost of concrete mix ratio. Specific methods are as follows:1. Test link. The testing and testing of various technical indicators of additives is an important link before procurement negotiations. Through tests, the qualified standards of various technical indicators of additives are determined, including solid content, water reduction rate, density, cement paste fluidity, concrete water reduction rate and other technical indicators. It is suggested that the water reduction rate of concrete should be taken as the key index to measure the quality level of admixture. 2. Procurement link. Once the additive eligibility criteria are clear, procurement negotiations can begin. It is recommended to invite tenders for additive manufacturers according to the qualification criteria determined by the test. On the premise that the quality level of admixture supply is not lower than the bidding requirements, the supplier shall be determined according to the principle of winning the bid at a low price. At the same time, the choice of additive manufacturers should consider the production scale, transportation distance, transportation capacity, supply experience and quality level of large-scale mixing plants or large-scale engineering projects, as well as after-sales service capabilities and levels. 3. Acceptance link. The admixture shall be tested before storage in the mixing station, and the test results shall be qualified according to the standards signed in the contract before storage. The key indicators of admixtures are water reduction rate and concrete water reduction rate, and the reference indicators are the density, solid content and fluidity of cement paste. Due to the testing time, the general technical indicators tested in the acceptance process are density, cement paste fluidity, and water reduction rate.

The concrete admixture can be put into storage only after it has been inspected before being put into storage and conforms to the standard stipulated in the contract. Since there will be some differences between the test results of water reduction rate and the test results of concrete mixing, it is recommended to conduct routine tests after the admixture is put into storage. The test items include concrete water reduction rate, solid content and other indicators, of which the concrete water reduction rate is the key indicator and must meet the requirements.

Key words:

Concrete admixture

The importance of concrete admixture to concrete quality

Analysis of the development status of concrete admixture in China

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