What is the harm of mica to concrete?
Mica not only affects the strength of concrete, but also affects the workability of concrete mixture, reduces the durability of concrete, and causes the expansion cracks of concrete.
The content of mica in aggregate is high, which will increase the water consumption of concrete, reduce the bond between aggregate and cement, and reduce the strength of concrete.
Mica is monoclinic, a laminated plate or book shaped crystal, usually said that the lamellar structure, easy peeling, low mechanical strength, hinder the normal cement formation cementation structure; in addition, chemical composition of mica containing magnesium and potassium, and the cement produced is not conducive to the strength formation reaction, such as alkali aggregate reaction.
When the content of mica in the aggregate reaches 2%, the workability loss of concrete is almost 50%; when the content of mica reaches 10%, the slump of concrete decreases to zero.
