The different forms of clay in sand have varying impacts on concrete.
If clay is wrapped around the surface of the aggregate, it will be detrimental to the bonding between the aggregate and cement, affecting the strength and durability of the concrete; If clay exists in loose particle form, due to its fine particles and large surface area, it will increase the water consumption of concrete.
Especially the unstable volume of clay, which shrinks when dry and expands when wet, can have a destructive effect on the dry and wet volume changes of concrete.
Overall, when the mud content of sand exceeds the standard, it will have adverse effects on the strength, shrinkage and creep, frost resistance, and abrasion resistance of concrete.
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