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The difference between early strength agent and accelerator

Release time:

2022-05-13

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Accelerator refers to the admixture that can make concrete set and harden quickly after mixing with concrete.

　　early strength agentIt refers to the admixture that can improve the early strength of concrete and has no significant effect on the later strength.

The main types of accelerators: carbonates and hydroxides of alkaline earth metals, sodium silicate (sodium silicate), potassium silicate accelerators, sodium aluminate accelerators, potassium aluminate accelerators and alkali-free liquid accelerators.

Based on the chemical composition,early strength agentIt can be divided into three categories: inorganic salts with strong electrolytes, water-soluble organic compounds, and composite compounds with organic and inorganic compounds.early strength agent.

The main component of the accelerator is alumina clinker (I. e., clinker made of bauxite, soda ash and quicklime in proportion), which is made by grinding.

In addition to chlorides and sulfates,early strength agentAlso included are chromates and organic substances such as triethanolamine, calcium formate, urea, etc.

The dosage of accelerator only accounts for 4% ~ 6% of the cement content in concrete, but it can make the concrete initial setting within 5min and final setting within 10min. So as to achieve the purpose of roadway repair or rapid pouring concrete. It is an indispensable additive in the shotcrete construction method. Their function is to accelerate the hydration and hardening of cement and form sufficient strength in a short time to ensure the requirements of special construction.

Theearly strength agentIt does not contain chloride ion and has no corrosion effect on steel bars. It is suitable for all civil and industrial buildings, prestressed reinforced concrete members and mortar. Suitable for construction at low temperature in early winter and early spring. It is used in Portland cement to enhance and modify slag cement.

Do not add accelerators when mixing materials. Because stones and sand contain a lot of water, the accelerator will absorb water and decompose its quick-setting components in a short time before spraying, affecting the setting time and reducing the strength of concrete, which leads to the adverse effects of sprayed concrete. The type of cement used in the project shall be tested before use and the dosage shall be selected before large-scale use.

　　early strength agentThe amount of cement is 3-6%. In order to keep the quality of the concrete mixed with the agent uniform, the mixing time is extended by 1-2 minutes. Concrete mixed with early strength agent cannot be used in orthopedics with active minerals (such as opal). This agent such as damp agglomeration, need to be crushed or weathered before use, performance unchanged.

Key words:

Early strength agent

Mechanism of action of early strength agent

The role of concrete early strength agent

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