The production process of artificial-sand, it needs to go through many processes such as crushing, screening, and sand-making, which will inevitably produce a large amount of stone powder. An appropriate amount of stone powder can improve the strength of concrete and reduce the risk of segregation and bleeding of its mixture under the action of hydration. However, if the content is too high, it is not conducive to the bonding between aggregate and cement stone and will reduce the performance of concrete. How much stone powder content should be controlled in artificial sand? How should the large content of stone powder be solved? Let’s take you to know more about it.
Standard of Artificial-sand
Machine-made Sand: Rock particles with particle size less than 4.75mm made by mechanical crushing and screening, but excluding particles of soft rock and weathered rock.
Ultra fine Sand: Natural river sand with fineness modulus of 0.7-1.5 tested according to the method specified in < < sand for construction > > (GB / T 14684).
Mixed Sand: Sand mixed with artificial sand and ultra-fine sand.
Manufactured Sand Concrete: Concrete prepared with manufactured sand as fine aggregate.
Mixed Sand Concrete: Concrete prepared with mixed sand as fine aggregate.
Plastic Concrete: Concrete with a slump of 10-90mm of the concrete mixture.
High Fluidity Concrete: Concrete with a slump of concrete mixture equal to or greater than 160mm.
The slump of concrete pumped for construction shall not be less than 100mm.
How much stone powder content should be controlled in artificial sand?
The stone powder content grades of artificial sand are 3%, 5%, and 7% respectively, which is relatively relaxed by 2% compared with the mud content of natural sand. In order to prevent the artificial sand from being mixed with excessive soil due to various factors in the mining and processing process, the artificial sand used in construction sand must pass the inspection of methylene blue MB value, and strict inspection and test shall be carried out on the site when the sand materials leave the factory (site) and construction.
The content of qualified manufactured sand and stone powder passing the MB value test of methylene blue shall be controlled by 3%, 5%, and 7%. For the test results of methylene blue value, the stone powder content of unqualified artificial sand is strictly controlled at 1%, 3%, and 5%, so as to avoid the adverse impact on concrete due to the high stone powder content of artificial sand.
For concrete, the content of stone powder is 10 ~ 15% of C30.
| Concrete | ≧C60 | C55-C30 | ≦C25 |
| Stone Power Content | ≦5.0% | ≦7.0% | ≦10.0% |
| Combined amount of needle and flake particles | ≦8% | ≦15% | ≦25% |
| Sediment Percentage | ≦0.5% | ≦1.0% | ≦2.0% |
| Clay Lump | ≦0.2% | ≦0.5% | ≦0.7% |
How to deal with the high content of stone powder in artificial sand?
- The feeding size of artificial sand shall be reasonable
The feeding size of artificial-sand materials shall meet the requirements of feeding standards. If the size is too large and the sand-making machine cannot be broken, the content of artificial sand and stone powder will increase, and the sand-making machine will be damaged in serious cases.
- Set screening link
Screen the excess stone powder content to improve the quality and quality of manufactured sand and make it meet the needs of construction sand.
- Equipped with sand washing equipment
After the materials are crushed and made into the sand, we can arrange sand washing equipment in the lower section of the sand-making machine. The wheel sand washing machine equipment can clean the excess stone powder, soil, and impurities in the artificial sand, which can perfectly control the content of the stone powder.
Go to the jaw crusher for crushing, then delivery to the fine jaw crusher
- Equipped with dust collection equipment
Equipped with dust collection equipment, use the fan to absorb the stone powder, and change the wind force by adjusting the power of the dust collection equipment, so as to control the content of stone powder and make the quality effect of manufactured sand more stable.