What are the main additives of concrete？

Concrete additives are an important part of modern concrete technology, the performance of concrete and construction effect has an irreplaceable role. When using concrete additives, it is necessary to choose the appropriate type and dosage in order to improve the performance index of concrete and reduce the cost as much as possible.

Ordinary concrete usually refers to the use of cement as cementitious material, sand and stone as aggregates, with water and admixtures in a certain proportion, after mixing. Concrete is widely used in civil engineering and is a building material necessary for the construction of basic infrastructure. 

Generally speaking, the main concrete additives are as follows：

1. Water reducing and plasticising agent

KDO liquid/flake type polycarboxylate superplasticizer is one of the most commonly used concrete additives, which can improve the working performance of concrete, such as reducing the viscosity of concrete, improving the fluidity, reducing the rate of water secretion, and increasing the construction time. Water reducing agent can be divided into water reducing type, collapse preservation type, slow release type, composite type, etc. according to its function.

2. Retarder

Retarder (antifreeze) is an additive to control the rate of concrete coagulation, commonly used in low-temperature concrete construction. Retarder can be divided into organic acid salts and chloride ions, etc., used to delay the setting time of concrete, to achieve the time required for construction operations.

3.Early strength agent

Early strength agent refers to additives that can promote cement hardening substances, that is, it can improve the strength development of concrete in a short period of time. It is usually used in cases where there is a need for rapid restoration of the load-bearing capacity of the site and the speed of construction. According to its chemical structure, it can be classified as carbonate type, hydroxylate type, silicate type and aluminates type.

4.Anti-cracking agent

The role of KDO's PP fibres in concrete mainly includes the following aspects: preventing shrinkage cracks in concrete, improving the fire resistance of concrete, enhancing the concrete toughness, improve the crack resistance of concrete, PP fibres can also improve the bond strength and stability of concrete, increase the toughness of the mixture and resistance to low temperatures, reduce the permanent deformation, and improve the anti-slip and wear-resistant ability.

5.Other additives

For different concrete uses and performance needs, you can also add a variety of special functions of the concrete additives, such as air-entraining agent, expansion agent, rust inhibitor, impermeable agent, pigment, fibre, chlorine salt shrinkage agent.

Concrete additives are an important part of modern concrete technology, the performance of concrete and construction effect has an irreplaceable role. When using concrete additives, it is necessary to choose the appropriate type and dosage in order to improve the performance index of concrete and reduce the cost as much as possible.