The Concept of Aggregate Particle Grading 5, the Concept of Aggregate Particle Gradation

Particle gradation of aggregates.

It is a key technology for the manufacture of concrete. A poor gradation of aggregate particles concrete, during the construction process, must be slurry, bone, water disintegration, pouring and molding arduous, and finally lead to the finished concrete "honeycomb, dog hole, hemp surface", low strength, poor durability. Therefore, aggregate as a building material commodity sold in the market, it is necessary to standardize its particle gradation in order to ensure the production and manufacturing of concrete.

Otherwise, it will lead to huge technical and economic losses for concrete works.

In order to mix concrete with good workability economically, foreign to sand.

The distribution of gradation requires that the particle content of less than 300UF should be in the range of 10% to 30%. It is recommended to maintain the content of 20% to 25% of hydraulic concrete in China, which is considered very necessary.

The U.S. Bureau of Reclamation has paid special attention to the classification of fine stones (5 19nn) into two grades: 10 19 mm and 5 10 mm. Among them, "bean stone" (5 10 mm) plays a key role in controlling concrete workability, concrete porosity and separation in aggregate transport. In China, it is divided into a "fine stone" level (5 20mm), which is extremely unfavorable to the performance of concrete.

Particle gradation is also known as (granular) gradation. The number of each level of particle size in a bulk material composed of different particle sizes. It is often used as a percentage of the total.

to represent. Composed of uninterrupted granularities of various levels of granularity, it is called continuous gradation; A discontinuous gradation consisting of only a few levels of granularity is called an intermittent gradation. Reasonable particle grading is an important way to achieve low porosity of ingredients.

A characteristic that reflects the morphology of the particle size distribution curve that makes up the soil.

Summary. Dear, hello, I am glad to answer for you the explanation of the noun of aggregate particle gradation is also known as (granular) gradation. The number of each level of particle size in a bulk material composed of different particle sizes.

It is often expressed as a percentage of the total. Particle gradation refers to the proportion of particles of various sizes in the aggregate. Aggregate gradation is the proportion of particles of different particle sizes that make up aggregates, aggregates are loose objects such as sand and gravel, and aggregate gradation is the proportion of particles of different particle sizes that make up aggregates.

That is, the proportion of aggregates containing different coarse and fine particles.

Dear, hello, I am glad to answer for you the explanation of the noun of aggregate particle Liang Kai gradation is also known as (granular) gradation. The number of each level of particle size in a bulk material composed of different particle sizes. It is often expressed as a percentage of the total.

Particle gradation refers to the proportion of particles of various sizes in the aggregate. Aggregate gradation is the proportion of particles of different particle sizes that make up aggregates, aggregates are loose objects such as sand and gravel, and aggregate gradation is the proportion of particles of different particle sizes that make up aggregates. That is, the aggregate contains the proportion of eggplant residue and locust with different coarse and fine particles.

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Dear, hello, I have inquired for you, what are the advantages and disadvantages of aggregates with good particle gradation; Particle gradation is an important performance index of aggregates, and the aggregates with good gradation have reasonable content of each particle size, neither too much nor too little, with low porosity, and can reduce water consumption and cementitious material consumption under the same condition of concrete working cultivation zone. A well-graded aggregate can reduce the porosity, and the fluidity of the concrete mixture can be maximized under the condition that the slurry remains unchanged. Aggregates with poor graded reeds have large voids.

Summary. Hello, dear, it is divided into three specifications according to the fineness modulus: coarse, medium and fine, and the fineness mode numbers are: coarse sand:

Medium sand: fine sand: Medium sand aggregate should be preferred when preparing concrete.

When coarse sand is used, the sand rate should be increased, and sufficient cement dosage should be maintained to meet the workability; When fine sand is used, it is advisable to reduce the sand rate appropriately.

Hello, dear, it is divided into coarse, medium and fine according to the fineness modulus, and the fineness mode numbers are: coarse sand: medium sand:

Fine sand: When preparing concrete, it is advisable to give preference to medium sand aggregates, such as muqi. When coarse sand is used, the sand rate should be increased, and sufficient cement dosage should be maintained to meet the needs of slag; When fine sand is used, the sand rate should be appropriately reduced.

What is the impact on the properties of concrete?

1) The effect of coarse aggregate grade pairing concrete performance stone grade matching refers to the distribution ratio of particle size particles at all levels. The gradation has a certain impact on the workability, strength, impermeability, frost resistance and economy of concrete, so the best gradation of stone of hydraulic concrete is through the combination of different particle sizes and different proportions, and the maximum tapped density is found by the drenched dense sail wildness method, so that the porosity of the combined coarse aggregate is the smallest. The use of coarse aggregate with good gradation can be used to prepare concrete with low cement consumption and good performance.

The larger the particle size of the coarse aggregate, the smaller the specific surface area that needs to be wetted. Therefore, large-volume concrete should be balanced with a larger particle size as much as possible.

Summary. 2. How to evaluate the coarseness and particle gradation of sand and stone aggregates? Hello dear, no, the classification of coarse, medium and fine sand is determined by the fineness modulus, coarse sand, medium sand, fine sand.

The fineness modulus mainly reflects the thickness of all particles, and does not fully reflect the gradation of particles. The particle gradation of sand is divided into 1 zone, 2 zone and 3 zone, which belongs to which zone data corresponds to according to the cumulative sieve percentage data of all levels of sieve holes. The fineness modulus and gradation of the sand should be considered at the same time when the concrete is configured.

2. How to evaluate the coarseness and particle gradation of sand and stone aggregates?

All right. Hurry up.

2. How to evaluate the coarseness and particle gradation of sand and stone aggregates? Hello dear, no, the classification of coarse, medium and fine sand is determined by the fineness modulus, coarse sand, medium sand, fine sand. The fineness modulus mainly reflects the thickness of all particles, and does not fully reflect the gradation of particles.

The particle gradation of sand is divided into zone 1, zone 2 and zone 3, which is based on the cumulative screen residue percentage data of each bright dust grade screen hole corresponding to which zone data range, which zone it belongs to. The fineness modulus and gradation of the sand resistance of the balance key should be considered at the same time when the concrete is configured.

The coarseness and fineness of the sand and the particle gradation are determined by the screening test of the sand service. Judge the thickness of the sand. Sands with different particle size distributions may have the same fineness modulus.

2. How to evaluate the coarseness and particle gradation of sand and stone aggregates?

Thank you, dear.

How to evaluate the fineness of the thick blades and particle gradation of sand and stone aggregates? The classification of coarse, medium and fine sand is determined by the modulus of fine silver, coarse sand starvation, medium sand and fine sand. The fineness modulus mainly reflects the thickness of all particles, and does not fully reflect the gradation of particles.

The particle gradation of sand is divided into 1 zone, 2 zone and 3 zone, which belongs to which zone data corresponds to according to the cumulative sieve percentage data of all levels of sieve holes. The fineness modulus and gradation of the sand should be considered at the same time when the concrete is configured.

Particle gradation refers to the copy it takes.

The size of the degree of attack, which has an impact on the cohesion and fluidity of concrete, refers to the workability or workability, the general pumping concrete has high requirements for this, he requires continuous gradation, not a single particle size.

Coarse degree refers to its size, there are coarse sand, medium sand, fine sand and extra-fine sand, general engineering is used for medium sand, fine sand specific surface area is large, the need for more cementitious materials, concrete cost is high.

Aggregate grading refers to the distribution of particles of different particle sizes in aggregates. A good gradation should result in a smaller aggregate porosity and total surface area, which not only reduces the amount of cement slurry required, but also improves the compactness, strength and other properties of the concrete. As shown in the figure below, if the particle size distribution of the aggregate is all within the same size range, a large void ratio will be generated;

Particle gradation of aggregates.

If the particle size of the aggregate is distributed in two size ranges, the porosity is reduced, as shown in the figure below;

Particle gradation of aggregates.

Particle gradation of aggregates.

It can be seen that only a suitable aggregate particle size distribution can meet the requirements of good gradation.

In the vernacular, it is the ratio of large stones to small stones and sand in the aggregate. Good grading means that the aggregate can be compacted.

Reduce the porosity and total surface area of aggregate, improve the strength and durability of concrete, improve workability, and save cement.