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The difference and connection between early strength agent and accelerator.

Release time:

2022-06-10

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Concrete early strength agent and accelerator are additives used to adjust the setting time and hardening performance of concrete, and are usually widely used in various construction projects. However, due to its similar functions, it is often misused and misused, which affects the quality of concrete projects and even causes engineering accidents in serious cases. In order to avoid such accidents, it is necessary to systematically analyze the difference and connection between early strength agent and accelerator. Let's understand the difference and connection between the early strength agent and the accelerator.

Concrete early strength agent is the admixture is one of the early use of admixture. So far, the industry has developed a variety of early strength agents, including chloride and sulfate, and on this basis, a variety of composite admixtures have been obtained, such as early strength water reducing agent, early strength antifreeze, early strength pumping agent and so on. Early strength agent according to its chemical composition can be divided into inorganic early strength agent, organic early strength agent and compound additives.

Concrete accelerator is an indispensable additive in shotcrete and rapid plugging materials. According to its state can be divided into powder accelerator and liquid accelerator. According to the content of alkali metal ions can be divided into alkaline accelerator, low alkali accelerator and alkali-free accelerator three. According to the main chemical substances, it can be divided into carbonate-containing alumina clinker, sulphoaluminate, water glass and low-alkali or alkali-free accelerator produced by aluminum sulfate. In addition, it has been reported at home and abroad that the organic-inorganic composite accelerator is composed of organic and inorganic substances. Its compressive strength develops rapidly, and it can greatly reduce the amount of dust and rebound in construction. However, the introduction of organic flocculants tends to affect the quick-setting effect of cement slurries.

The type, performance, function and mechanism of early strength agent and accelerator are very different, and the application occasions are also very different. In the concrete production process, adding early strength agent can significantly improve the early strength of concrete without affecting its later strength, and can greatly shorten the curing time. Therefore, the early strength agent is mostly used in winter construction and concrete component production. In winter construction, it is generally necessary to add early strength agent to the concrete with early strength requirements to shorten the demoulding curing time and speed up the construction progress, so as to effectively improve the construction efficiency and save the concrete construction cost. According to statistics, the total amount of early strength agent used in China is nearly 200000 tons per year. Because the setting time of the accelerator is very short, it cannot ensure that the concrete is fully mixed and poured in a short time before the initial setting, so it is not suitable for the general formwork method of pouring concrete. Therefore, accelerator should not be used in general works.

In summary, early strength agent and accelerator are two completely different concrete admixtures, which are very different in definition, classification, mechanism of action and use. However, the two additives have many similarities in composition and hydration reaction, which is very easy to cause confusion. Therefore, in the construction project, it is necessary to reasonably select the early strength agent and accelerator according to the type of project, and select the appropriate type of early strength agent and accelerator according to the characteristics and requirements of the project to prevent misuse and misuse, so as to ensure the quality of the project and avoid the occurrence of engineering accidents.

Key words:

Early strength agent

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