What about mortar cracks? How to construct?
Plastic crack
Principle explanation
Plastic cracking refers to the cracking of the mortar before or during hardening. It generally occurs in the early stage of mortar hardening. The plastic cracking cracks are generally coarse and the crack length is short.
Cause Analysis
It is mainly related to the material properties of the mortar itself and the ambient temperature, humidity and wind speed. The higher the amount of cement, the smaller the modulus of sand fineness, the higher the mud content, the larger the water consumption, and the more likely the mortar is to be plastically cracke. The higher the ambient temperature, the lower the humidity, and the higher the wind speed, the more likely the mortar will be plastically cracked.
Prevention
In the mortar, by adding water-retaining thickener and admixture, the amount of cement is reduce, the fineness modulus of the sand and its mud content are control, the water consumption is reduce, the environment during construction is control, and the climatic conditions of high temperature drying and windy are avoid as much as possible. , thereby reducing the risk of plastic cracking.
Dry shrinkage cracking
Principle explanation
Dry shrinkage cracking refers to the cracking of the mortar after hardening. It generally occurs in the later stage of mortar hardening, and the dry shrinkage crack is characterized by thin and long.
Cause Analysis
The main reason for the occurrence of dry shrinkage is the large amount of cement in the mortar and the high strength. Lead to volume shrinkage; maintenance of later mortar is not in place.
The mixture or mixture material incorporated into the mortar itself has a large dry shrinkage value. The wall itself is crack, the interface is not properly hand; the mortar level is disorder or misused, and the elastic modulus of the substrate and mortar is too different.
Prevention
Reduce the amount of cement, add appropriate amount of admixture, reduce the shrinkage value.The construction company strengthens the promotion and guidance of the relevant personnel’s business knowledge and strengthens management.
Strict requirements from all aspects, and construction according to pre-mixed mortar construction methods.
If you have any questions, you can send them to my email : tanyatao@qinahaochem.com
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