Three typical problems in using concrete admixtures

The first question: How to find the optimal dosage of admixtures? Are you looking for the adaptability of admixtures and cement? Please be more detailed.

Second question: It is more troublesome to determine the water reduction rate of admixtures. Can it be replaced by the water reduction rate of mortar? Is it accurate?

The third question: If the water reduction rate of the admixture is 20%, and the water consumption per cubic meter of concrete without admixture is 260KG, then How should the water reduction rate of this admixture be calculated? Is it related to the dosage? Is the water reduction rate the same between 1.8% and 3% admixtures? Or is the water reduction rate different depending on the dosage? How to convert specifically?

1. The optimal dosage of admixture is found by the water reduction rate of the admixture. The water reduction rate achieved according to the requirements of the instruction manual is the same as the actual dosage. The optimal dosage is achieved to achieve such a water reduction rate.

2. You can use the water reduction rate of mortar instead. There will be a slight error. If the raw material is not good, the error will be large. If the raw material is good, the error will be small. The main reason is that it contains Mud amount and stone powder content

3. “So how should the water reduction rate of this admixture be calculated? Is it related to the dosage?” It is known to be 20% , and asked how to calculate it? How should the water consumption be calculated? Just 260*80%. The dosage of different admixtures is different. 1.8 and 3 are not sold by the same company, but the prices are also different. It depends on the cost-effectiveness, no matter how much the dosage is. The water reduction rate must meet the specified requirements. This is a must. There is no way to convert it.

Admixture. Substances are added during the concrete mixing process to improve the properties of concrete. The dosage is generally no more than 5% of the cement mass. They are divided into four categories according to their main functions: (1) Admixtures that improve the concrete mix and workability properties, including various water reducing agents, air-entraining agents, pumping agents, etc.; (2) Admixtures that adjust the setting time and hardening performance of concrete. Admixtures, including retarder, early strength agent, accelerating setting agent, etc.; (3) Admixtures to improve the durability of concrete, including air entraining agents, waterproofing agents, rust inhibitors, etc.; (4) Admixtures to improve other properties of concrete. Agents, including air-entraining agents, expansion agents, antifreeze agents, colorants, waterproofing agents and pumping agents, etc.

Referred to as admixture. Substances are added during the concrete mixing process to improve the properties of concrete. The dosage is generally no more than 5% of the cement mass. They are divided into four categories according to their main functions: (1) Admixtures that improve the concrete mix and workability properties, including various water reducing agents, air-entraining agents, pumping agents, etc.; (2) Admixtures that adjust the setting time and hardening performance of concrete. Admixtures, including retarder, early strength agent, accelerating setting agent, etc.; (3) Admixtures to improve the durability of concrete, including air entraining agents, waterproofing agents, rust inhibitors, etc.; (4) Admixtures to improve other properties of concrete. Agents, including air-entraining agents, expansion agents, antifreeze agents, colorants, waterproofing agents and pumping agents, etc.

Edit this paragraph 1. Introduction

1.1 This standard applies to cement concrete admixtures Classify and name, and define each named admixture. 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 cement paste or mortar admixtures. 1.2 Each admixture 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 shall not exceed 5% of the cement mass (except in special circumstances). 1.4 This standard refers to the draft international standard ISO/DIS 7690.

Edit this paragraph 2. Classification of concrete admixtures

Concrete admixtures are classified according to their main The functions are divided into four categories: 2.1 Admixtures that improve the rheological properties of concrete mixtures. Including various water reducing agents, air entraining agents and pumping agents, etc. 2.2 Admixtures used to adjust the setting time and hardening properties of concrete. Including retarder, early strength agent and quick-setting agent. 2.3 Admixtures to improve the durability of concrete. Including air-entraining agents, waterproofing agents and rust inhibitors. 2.4 Admixtures that improve other properties of concrete. Including air-entraining agents, expanding agents, colorants, waterproofing agents and pumping agents, etc.

Edit this paragraph 3. Name and definition of concrete admixture

3.1 Water reducing agent

Ordinary water-reducing admixture is an admixture that can reduce the amount of mixing water when the slump of concrete is basically the same. Commonly used water reducing agents are anionic surfactants. High-efficiency water-reducing admixture superplasticizer is an admixture that can significantly reduce mixing water consumption under the condition that the slump of concrete is basically the same. Set retarding and water-reducing admixture is an admixture with both retarding and water-reducing functions. Hardening accelerating and water reducing admixture Hardening accelerating and water reducing admixture An admixture with both early strengthening and water reducing functions. Air entraining and water reducing admixture Air entraining and water reducing admixture An admixture with both air entraining and water reducing functions. </p