Can red fly ash be used as aerated concrete

The premise of making aerated concrete is that you need to understand what the whole production process is like, you can go to the encyclopedia to understand, I will only give you some simple answers based on my actual work.

First of all, the production of aerated concrete and other aerated concrete wall materials (such as blocks and wall panels) is a chemical reaction, simply put, it is a hydration reaction to generate silicates, in which the main chemical components include silicon, calcium, aluminum (aluminum powder is used as a gassing agent) and acid groups (silicate, carbonate, etc.) contained in raw materials generated through chemical reactions

So no matter what color of fly ash is required to test, the red fly ash you are talking about, I guess it may be because it contains a certain composition higher (the possibility of containing iron is greater), for the raw material requirements for making aerated concrete, the corresponding national standards will be listed in the national standards for aerated concrete and other aerated concrete wall materials (home page description), you can refer to the standard when choosing. But it is not that the fly ash that has errors with the national standard can not be used, first of all, you should conduct a chemical analysis of the fly ash, find out which chemical composition causes the fly ash to turn red, if the component is not the component required in production, then you should use it carefully or do not use, if it is needed, then according to the chemical ratio, to determine the amount of fly ash, improve the formula process (non-professionals do not try, time-consuming, laborious and costly).

Here you are provided with the fly ash selection criteria mentioned in the national standard for aerated concrete blocks.

GB11968-2006 aerated concrete block standard, Section II normative reference document mentions the JCT409 standard, that is, the fly ash standard for silicate building products.

The red fly ash you mentioned should be chemically separated, and if the index exceeds the standard, it should be considered separately.

The role of fly ash in concrete is:

1. Fly ash can play an active role in concrete, which can make the gap between cement and coal ash smaller.

2. It plays the role of filling, which can improve the structural density.

3. It has a morphological effect, because it does not have strong adsorption to water. It has good liquidity.

What is the role of fly ash in concrete.

Where the family is, the heart is at peace.

1. Fly ash can play an active role in concrete, making the gap between cement and coal ash smaller. 2. It plays the role of filling, which can improve the structural density. 3. It has a morphological effect, because it does not have strong adsorption to water.

It has good liquidity.

The effect of adding fly ash to concrete is to reduce the material used in cement, so that the workability of concrete is relatively better and the cost is low.

Yes, fly ash is only an application of modern concrete to pursue low cost and high performance, the previous concrete is not fly ash, but mixed with an appropriate amount of fly ash is a certain benefit, not only can replace part of the cement to save costs, but also can increase the fluidity of concrete, reduce the heat of hydration to prevent cracks.

The above paragraph is borrowed from the following netizens, and I will add it myself.

Fly ash can effectively improve the workability of cement concrete, so that its working performance is better, of course, how much fly ash is mixed with regulations, highways, water transportation are different regulations.

Getting back to the point, concrete can be done without fly ash! If it is a large volume of concrete, then it is recommended to add fly ash, because the appropriate fly ash can be mixed to properly reduce the hydration heat of cement, because the hydration heat of cement will produce cracks, compared to the large volume of concrete.

If you don't count the cost, it is no problem not to add fly ash, the advantage of adding fly ash is to reduce the cost of cement, instead of cement, the second is to reduce the heat of hydration, the third is to improve the workability of concrete, the concrete with fly ash is added in the early stage because of the limitation of the heat of hydration, so the early strength is lower than that of the concrete without fly ash, but the later stage is considerable, the later stage refers to the strength of 28 days, and after 28 days, it can continue to increase some MPA.

It's a little scattered, if you can ask targeted questions, I can you.

Yes, fly ash is mainly used for the configuration of light aggregate concrete, while general concrete does not need to add fly ash.

Light aggregate concrete is divided into natural light aggregate only aggregate concrete according to the type of light aggregate. Such as pumice concrete, porosyl concrete and porous tuff concrete.

Artificial light aggregate concrete. Such as clay ceramsite concrete, shale ceramsite concrete, expanded perlite concrete and concrete made of light aggregate (polyurethane particles). Industrial waste light aggregate concrete.

Such as cinder concrete, fly ash ceramsite concrete and expanded slag bead concrete.

What is the role of adding fly ash to concrete???

Hello: Adding fly ash to concrete Effect: 1. Mixing fly ash can improve the workability of fresh concrete.

2. Fly ash can inhibit the water leakage of fresh concrete 3. Mixed with fly ash can improve the later strength of concrete 4. Mixed with fly ash can reduce the heat of hydration of concrete 5. Mixed with fly ash can improve the durability of concrete.

The water-reducing effect of fly ash makes the drying shrinkage and early plastic drying cracking of fly ash concrete basically the same or slightly lower than that of ordinary concrete, but inferior fly ash will increase the drying shrinkage of concrete.

Fly ash mainly contains silica (SiO2), alumina (Al2O3) and iron oxide (Fe2O3), etc., which have been widely used in cement making and various lightweight building materials. In addition, fly ash can also be used as drifting beads and as fertilizer and trace compound fertilizer. In the industrial aspect, it can be used from fly ash to extract a variety of substances such as iron, carbon, copper, germanium and scandium.

The density is grams of cubic centimeters.

Features of concrete:

Concrete has the characteristics of abundant raw materials, low cost and simple production process, so that the amount of concrete is getting larger and larger. At the same time, concrete also has the characteristics of high compressive strength, good durability and wide range of strength grades.

These characteristics make it widely used, not only in various civil engineering projects, but also in shipbuilding, machinery industry, marine development, geothermal engineering, etc., concrete is also an important material.

Adding fly ash to concrete can improve the workability of concrete, improve the pumpability and durability of concrete, so it is widely used in many concrete structure buildings. In order to use fly ash correctly, there are several problems that should be paid great attention to during construction. The following is an introduction to the main content of the requirements for the use of concrete fly ash brought by Zhongda Consulting for reference.

Due to the classification of fly ash, there are specific requirements for the indicators of cracking or each level at the same time, so it is inevitable to make specific limits for the application scope of fly ash

1) Grade fly ash is suitable for reinforced concrete, and is allowed to be used for post-tensioned prestressed reinforced concrete components and pre-tensioned prestressed reinforced concrete components with a span of less than 6m (excluding 6m).

2) Grade fly ash is mainly used for ordinary reinforced concrete structures.

3) grade fly ash (including wet ash discharge that reaches the grade fly ash index), mainly used for concrete with strength grade below C15 without any reinforcement.

When selecting fly ash on the construction site, attention should be paid to the classification of fly ash and the limitation of the application range.

2) Under normal temperature construction conditions, fly ash concrete should be used in combination with admixtures to further improve the workability of concrete, improve pumpability and durability of concrete. For example, fly ash is used in combination with pumping agent, and the effect is very obvious.

3) During the construction in winter, the composite early strength antifreeze should be mixed to improve the early strength of fly ash concrete.

4) Fly ash should be accepted by a special person when entering the site, and the factory certificate should be verified, which should include: the name and batch number of the factory, the number and date of the certificate, the grade and quantity of fly ash.

5) The batch of fly ash sampling is calculated as a batch of continuous **200t fly ash of the same grade, and when it is less than 200t, it is also calculated as a batch. The measurement of fly ash is calculated by weight of dry ash (moisture content less than 1%).

For bulk fly ash sampling, 15 samples can be taken from different parts of each batch, each part is not less than 1kg (generally can be mastered at 1 3kg), and after mixing and mixing, the sample (average sample) is twice as large as the amount required for the test according to the quarter method.

For bagged fly ash sampling, 10 bags can be drawn from each batch, and no less than 1kg of samples can be taken from each bag, mixed and mixed, and the sample (average sample) that is twice the amount required for the test is reduced according to the quarter method.

6) If the supply of fly ash is relatively stable, when the cumulative quantity of fly ash is less than 200t, the inspection of fly ash fineness should be sampled at least once a day, and the loss of ignition should be inspected at least once a quarter.

7) When fly ash is stored in Huaiyuan lead, because its appearance color is similar to cement, it must not be mixed with cement to avoid misuse, and it should be considered to set up a separate storage room or storage silo at the lead application site, and hang obvious signs in the storage place.