4 Mortar hollowing problem
1. Constructive hollowing
The roughness of the interface agent is insufficient or the plaster layer is loosened due to rubbing and pressing before the mortar is collected. Or the mortar itself has insufficient bonding strength. Cause peeling between the mortar layer and the interface agent layer.
2. Shrinkage empty drum
The base treatment is not standardized or the cohesive force of the interface layer is lower than the shrinkage stress between the mortar and the interface layer. Cause the interface agent layer to peel off from the base layer.
The adhesion between the ready-mixed mortar itself and the smooth shear wall is far from enough. Therefore, an interface agent must be used.
The function of the interface agent is to increase the bonding force between the mortar and the shear wall. And increase the contact area between the mortar and the wall. Thus, the shrinkage stress between the mortar and the wall can be evenly distributed. Effectively avoid the phenomenon of large-area hollowing caused by excessive shrinkage stress concentrated in one place.
At present, the most commonly used method on the construction site is to add construction glue and cement to pat the interface. But quite a lot of projects still have more quality accidents of mortar hollowing. The reason is that the construction in this way is arbitrarily large.
The method of hair spraying with air compressor and spray gun is becoming more and more common. And use the I-type concrete interface treatment agent produced by professional manufacturers to solve the problem of too wide nap spacing or missing nap. Because its construction is relatively easy and labor-saving. Everywhere can be sprayed in place. The spray point is even and rough, and the cohesive force is strong, which can effectively disperse the shrinkage stress generated during the drying and hardening of the mortar.
5.The cracking problem of plastering mortar on the wall
1. Strictly control the sand rate to be greater than or equal to 78%.
2. Strictly control the mud content of the sand to not exceed 3%.
3. Try to avoid the use of mortar tailings.
Five major quality problems of wet-mixed mortar and their solutions(1)