Cracking of dry-mixed mortar is divided into plastic cracking and shrinkage cracking. Next, Landcel will help you analyze the two situations in detail.

1. What is plastic cracking of dry-mixed mortar?

Plastic cracking refers to the cracking of mortar before or during hardening. It generally occurs in the initial stage of mortar hardening. Plastic cracking cracks are generally thicker, and the crack length is short.
Reason analysis: shortly after the mortar is plastered, shrinkage stress occurs due to the rapid reduction of moisture in the plastic state. When the shrinkage stress is greater than the bond strength of the mortar itself, cracks will appear on the surface.
1.1 It is often related to the material of the mortar and the ambient temperature, temperature and wind.
1.2 The larger the amount of cement, the smaller the sand fineness modulus, the higher the mud content, and the larger the water consumption, the easier it is for the mortar to crack plastically.

2. What is shrinkage and cracking of dry-mixed mortar?

Shrinkage cracking refers to the cracking of mortar after hardening. It generally occurs in the late stage of mortar hardening. Shrinkage cracking, the crack is characterized by thin and long.
Reason analysis: Shrinkage cracking is the crack caused by water loss and volume shrinkage after the mortar hardens. It generally takes a year or even 2 to 3 years before it gradually develops.
2.1 The amount of mortar cement is large, and the strength is too high, resulting in volume shrinkage.
2.2 The late maintenance of mortar is not in place.
2.3 The drying shrinkage value of the mortar admixture or admixture is large.
2.4 The wall itself is cracked and the interface is not handled properly.
2.5 The label of mortar is used indiscriminately or wrongly, and the elastic modulus difference between the base material and the mortar is too large.
Preventive measures: reduce the amount of cement, add suitable admixtures to reduce the dry value. Strengthen publicity and guidance to the construction party, strengthen management, and strictly require construction according to the ready-mixed dry-mixed mortar construction method.