Classification, naming and definition of concrete admixtures

1 Introduction

1.1 This standard applies to the classification and naming of cement concrete additive dosage, and defines each type of additives. Named admixtures are defined. Every product that meets the definition of concrete admixtures in Chapters 2 and 3 of this standard shall belong to a certain category of this standard and be given a name.

This standard also applies to admixtures for cement paste or mortar

1.2 Each admixture It is defined according to one or more functions it has and named according to its main function. Compound admixtures have more than one main function and are named according to more than one function.

1.3 Concrete admixtures are substances added during the concrete mixing process to improve the properties of concrete. The dosage should not exceed 5% of the cement quality (except for special circumstances).

1.4 This standard adopts the draft international standard ISO/DIS 7690

2. Concrete additive dosage Classification

Concrete admixtures are divided into four categories according to their main functions

2.1 Improving concrete mixing logistics Modifying admixtures. Including various water reducing agents, air entraining agents and pumping agents, etc.

2.2 Admixtures that adjust the setting time and hardening performance of concrete. Including retarder, early strength dosage and accelerating setting agent, etc.

2.3 Admixtures that improve the durability of concrete. Including air-entraining agents, waterproofing agents and rust inhibitors.

2.4 Admixtures that improve other properties of Authentic. Including air-entraining agents, expansion agents, antifreeze agents, colorants, waterproofing agents, and pumping agents, etc.

3 Name and definition of concrete admixture

3.1 Ordinary water-reducing admixture

An admixture that can reduce the amount of mixing water when the slump of concrete is basically the same.

3.2 Hardening accelerator

Admixture that accelerates the early strength development of concrete.

3.3 Retarder set retarder

Admixture that prolongs the setting time of concrete.

3.4 air entraining admixture

In the process of mixing concrete, it can introduce a large amount of evenly distributed, Stable and closed micro-bubble admixture.

3.5 superplasticizer

Under the condition that the concrete slump is basically the same, it can An admixture that significantly reduces the water consumption of the mixture.

3.6 hardening accelerating and water reducing adminxture

Has both early strength and water reducing adminxture Admixture with water function

3.7 set retarding and water-reducing admixture

An admixture with both retarding and water-reducing functions.

3.8 air entraining and water reducing admixture

It has both air entraining and water reducing admixture Admixture for water function.

3.9 water repellent admixture

An external additive that can reduce the water permeability of concrete under hydrostatic pressure agent.

3.10 anti-corrosion admixture

Can inhibit or reduce the corrosion resistance of steel bars or other preservatives in concrete Admixture for burying metal rust.

3.11 Gas forming admixture

Gas is released due to chemical reactions during the concrete preparation process , which causes the formation of a large number of pores in the concrete.

3.12 Expanding admixture

An admixture that can cause a certain volume expansion of concrete.

3.13 anti-freezing admixture

can harden concrete at negative temperatures and Admixtures that achieve sufficient antifreeze and strength within the specified time.

3.14 coloring admixture

Admixtures that can prepare concrete with stable colors.

3.15 accelerating setting admixture

An admixture that can quickly solidify and harden concrete.

3.16 Pumping aid

Admixture that can improve the pumping performance of concrete mixtures .

Additional notes:

This standard is developed by the Institute of Building Materials Science, China Academy of Building Sciences, Suzhou Concrete and Cement Products Research Institute, Shanghai Institute of Building Research, Railway Research Institute, Nanjing Water Conservancy Research Institute, Water Science and Hydropower Research Institute, Yangtze River Academy of Sciences, Metallurgical and Construction Research Institute, Tongji University, and Tsinghua University were responsible for drafting.

The main drafters of this standard are Huang Daneng, Wu Zhaoqi, and Chen Jinchuan.

National Standard of the People's Republic of China

���Concrete admixture GB 8076—1997

1. Scope

This standard specifies the use The definition, technical requirements, test methods, inspection rules, packaging, delivery, storage and return of admixtures in cement concrete.

This standard applies to ordinary water-reducing agents, high-efficiency water-reducing agents, retarding high-efficiency water-reducing agents, early-strength water-reducing agents, retarding water-reducing admixtures, and primers. Gas water reducing agent,</p