Plastering mortar foaming

[Scott Kaplan]

After polishing the plastering mortar on the interior wall, the concrete wall will bulge in about 2 hours. I don't know what caused it.
Cement 235, stone powder 58, machine-made sand 798, river sand 532, thickener 5.5, conditioner 2.5, water 200.

 

[Alex]

Measure the apparent density to see if too much air-entraining agent is added and if the wall is wetted with water.

 

[Shamil]

The base layer should treat appropriately, lowering the mortar's viscosity and improving the air permeability.

 

[Luis]

It may be related to the caking and poor dispersion of one of your additives.

 

[Cassie]

We have encountered this situation. There are air bubbles on plastered concrete walls, but there are no bubbles on block or brick walls. The main reason is that the concrete walls have many pores and are airtight. The gas has to discharge outside so that plum up the mortar. It can optimize from the following aspects: 1. brush interface agent on concrete wall, which can solve the problem entirely; 2. If the mortar becomes too dense, it can replace with river or machine-made sand, but it is hard to solve completely.

 

[Ankur]

The gradation of the sand should match appropriately if making the formula for more than 1.6 tons of aggregate. Using too many additives will have a negative effect.

 

[Chanliss]

Reduce the amount of additives, which mainly depends on the gradation of the sand;using fine sand will cause bulge.

 

[Ramon Doria]

Powder adding is too much; I assume the powder content of the finished product will not be less. Therefore, it is better to sieve the finished product to see if there is too much powder. In addition, the sand gradation should be reasonable; the coarser, the better.

 

[Allen]

It means that the air in the concrete is wetted by water, and the air discharges into the mortar. However, the mortar is too sticky or contains too much powder, so the gas cannot release normally and can only bulge inside. There are two adjustment ideas: one is to apply an adhesion agent on the concrete to close the pores; the other is to adjust the mortar ratio and reduce the viscosity of the wet mortar and the powder content. The two strategies can solve the problem.