Home → News → What is the aggregate? Why is it important? Every mining person should know

What is the aggregate? Why is it important? Every mining person should knowPosted: 2018-07-10

Aggregate is a granular loose material that is erected or filled in concrete. It can provide good stability of concrete and better durability than cement stone. It can reduce shrinkage, inhibit crack propagation, transmit force and reduce hydration. Heat, provide wear resistance and so on. By adding as much aggregate as possible without affecting the performance of the concrete, the cost of the concrete can be reduced.

Fine aggregate and coarse aggregate are the classification of aggregates often mentioned in production. Let's take a closer look.

Fine aggregate - sand
The rock particles with a particle size between 0.15 and 4.75 mm are fine aggregates, commonly known as sand, and are classified into natural sand and artificial sand according to the source of production.

Natural sand is a rock particle with a particle size of less than 4.75mm formed by natural weathering, water flow handling and sorting and accumulation, but does not include particles of soft rock or weathered rock. Natural sands include river sand, lake sand, mountain sand and desalinated sea sand.
The surface of sea sand particles is smooth and clean, but often contains harmful substances such as broken shells and soluble salts. The mountain sand particles are angular and have a rough surface, containing a lot of mud and organic impurities. The machine-made sand is made by mechanical crushing of natural rock and sieved. The mixed sand is a mixture of natural sand and artificial sand without a fixed mixing ratio.

Coarse aggregate - stone
Aggregates with a particle size between 4.75 and 9.0 mm are coarse aggregates, commonly known as stones, and are commonly used in both gravel and pebbles.

Crushed stone is a rock of natural rock or rock that has been mechanically broken and sieved and has a particle size greater than 4.75 mm. Pebble is a rock particle with a diameter larger than 4.75mm, which is formed by natural weathering, water flow, sorting and accumulation. It can be divided into river pebble, sea pebble and mountain pebble according to its source.

Aggregate requirements in concrete
As the main raw material in concrete, aggregate plays a role in skeleton and support in buildings. When mixing, the cement is stirred into a thin paste by water. If no aggregate is added, it will not be formed and will eventually be unusable, so the aggregate is an important raw material in the building. What are the requirements for the aggregate in concrete?
1) It has a good particle grading, so that the small void ratio is always lower than the surface to reduce the amount of cement slurry;
2) The surface of the aggregate particles is clean to ensure good adhesion to the cement slurry;
3) Ingredients containing less harmful impurities, which shall not affect the cement hardening and durability of the later mixed soil;
4) It has sufficient strength and firmness to ensure the transmission of the skeleton.
Aggregates have a wide range of applications in civil engineering, such as cement concrete, asphalt concrete, road foundation, railway track slag, mortar, etc., with an annual consumption of about 2 billion tons. The huge demand has driven the development of the aggregate market.

We can use the crusher and grinding mill to make aggregate. Know more about grinding mill of Shanghai Clirik.

Previous：Clirik Micro Powder Grinding Mill Use In Vietnam/Vietnam Clients' Work Site: Next：How To Choose Gypsum Powder?