What is the fineness of fly ash
Fly ash is an industrial by-product of emissions from coal-fired power plants and has been widely used in the fields of building materials, environmental protection, etc. in recent years. Its fineness is one of the important indicators for measuring the quality of fly ash, which directly affects its physical and chemical properties and application effects. This article will analyze in detail the definition of fly ash fineness, measurement methods and its impact on engineering applications based on the popular topics and hot contents of the entire network in the past 10 days.
1. Definition of fly ash fineness
The fineness of fly ash refers to the coarseness and fineness of its particles, which is usually expressed in terms of specific surface area or sieve margin. The higher the fineness, the stronger the fly ash is, and the filling effect and volcanic ash effect can be better exerted in materials such as concrete. Here are common categories of fly ash fineness:
| Fineness classification | Specific surface area (m²/kg) | Sieve allowance (45μm sieve) |
|---|---|---|
| Coarse fly ash | 200-300 | 25%-40% |
| Medium fine fly ash | 300-400 | 12%-25% |
| Fine fly ash | 400-600 | ≤12% |
2. Methods for measuring fly ash fineness
At present, there are two main methods for measuring fly ash fineness:
| Measurement method | principle | Applicable standards |
|---|---|---|
| Screening method | Calculate fineness through the sieve allowance of 45μm screen | GB/T 1596-2017 |
| Bosch's specific surface area method | Determination of specific surface area by air permeability | GB/T 8074-2008 |
The screening method is simple to operate, but it is greatly affected by the shape of the particles; the Bosch specific surface area method is more accurate, but the equipment cost is higher.
3. The impact of fly ash fineness on engineering application
The fineness of fly ash directly affects its performance in concrete, cement and other materials. The following are the specific impacts of fineness on engineering applications:
| Application areas | Detail requirements | Influence effect |
|---|---|---|
| High performance concrete | Specific surface area ≥400m²/kg | Improve strength and durability |
| Ordinary concrete | Specific surface area 300-400m²/kg | Improve workability and reduce hydration heat |
| Cement mix | Sieve balance ≤12% | Enhance volcanic ash activity |
4. Hot content about fly ash in the entire network in the past 10 days
Through the compilation of popular topics across the network for the past 10 days, we found the following hot content related to fly ash:
| Hot Topics | Main content | Popularity index |
|---|---|---|
| Application of fly ash in carbon neutrality | Exploring the potential of fly ash as a carbon sequestration material | ★★★★ |
| Effect of fly ash fineness on concrete properties | Study the filling effect of fly ash of different fineness | ★★★ |
| New technology for resource utilization of fly ash | Introduction to the preparation process of ultrafine fly ash | ★★★ |
5. Summary
The fineness of fly ash is a key indicator of its quality, which directly affects its application effect in the fields of building materials, environmental protection, etc. The fineness of fly ash can be accurately measured by screening or Berthal specific surface area method, and the appropriate fly ash type can be selected according to different engineering needs. With the advancement of resource utilization technology, the application prospects of fly ash will be broader.
In the future, the preparation technology of ultrafine fly ash and its application in carbon neutrality will become research hotspots and deserve continuous attention.
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