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Analysis of the causes and effects of excessive mud content in sand and gravel aggregates!

Release time:Apr.17.2024 Views:0

Sand and gravel aggregate is a basic component of concrete,(stone crusher) a building material. With the development of infrastructure construction, the demand for sand and gravel aggregate is increasing. In order to improve the quality of construction projects, my country has clear regulations on the mud content of sand and gravel aggregates, which requires the particle size of the mud content in concrete to be less than 80um, and different concrete strength levels have different mud content standards. It is understood that sand and gravel aggregates in concrete account for about 70% of the total mass of concrete. Therefore, the quality of sand and gravel aggregates has a decisive impact on the performance of concrete.


Analysis of the reasons for high mud content in sand and gravel aggregates


The main reasons for the excessive mud content of construction sand and gravel during the production process are as follows: excessive weathering of interlayers in the stone, low strength of the stone, resulting in excessive mud content in the manufacturing of sand and gravel aggregates, or failure to adjust the eccentric block of the vibrating screen, It is caused by the failure of buffer materials on the vibrating screen and the unreasonable layout of plate drainage pipes.

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The impact of high mud content in sand and gravel aggregates


When the mud content in concrete far exceeds the actual required standards, the mud will directly affect various performance indicators of concrete, especially the production and construction process of commercial concrete. Therefore, construction personnel must understand It is of great practical significance to understand the influence of sand and gravel aggregates with high mud content on the performance of concrete.


1. It causes an increase in water demand, reduces the holding force of cement slurry on coarse aggregate, reduces the density of concrete, and thereby reduces the strength of concrete. (Generally, if the mud content of sand exceeds 2%, it will have an adverse effect on the strength of concrete)


2. It has an adsorption effect on admixtures, which affects the solidity of concrete and causes a significant decrease in slump.


3. Increase the dry shrinkage of concrete, reduce the bonding strength of the concrete aggregate interface and the tensile strength of concrete, and easily cause cracking of concrete.


4. Soil is not easy to participate in the hydration reaction, which will affect the normal hydration reaction of cement and easily lead to cracks inside the concrete, thereby reducing the durability of the concrete, making it easy to weather, affecting the resistance to freeze-thaw and impermeability, and shortening the service life of the concrete. .


5. The internal friction between cement and gravel will decrease, while the internal stress will increase, leading to sliding cracking and reduced strength. It may also cause corrosion of steel bars and reduce the strength of steel bars.


6. It affects the uniformity of concrete, forms unsealed air spaces, and significantly reduces frost resistance. Under freeze-thaw conditions, the shrinkage ratio is different from that of concrete, affecting the durability of concrete.

2

750 wheel bucket sand washing machine


Xingao Heavy Industry Wheel Bucket Sand Washing Machine is a device for cleaning the mud powder and other dust particles attached to the surface of the sand and gravel after the ore is crushed. It can effectively remove the stone powder, soil, and fine sand and gravel particles from the finished sand and gravel aggregates. It can be cleaned and filtered out, and the particle size of the finished sand and gravel can be controlled by controlling the mesh number of the washing screen, so that the content of fine sand particles and stone powder can be controlled within a certain proportion, thereby improving the overall sand and gravel quality.