Two days after finishing cement-based self-leveling, the surface layer has intensity, but not the middle level after polishing, and back to the sand.

C

Chanliss

Member
Here is the formula,

ordinary Portland cement 250
sulfoaluminate cement150
Heavy Calcium Carbonate 100
80－120size Sand: 450
Gypsum 50
Cellulose 1.0
Redispersible Polymer powder 10
polycarboxylate superplasticizer 1.0
Tartaric acid 0.7
sodium gluconate 0.4
Antifoaming agent 1.0
Suspension stabilizer 1.0
Water 26%
Initial fluidity 140mm
Twenty minutes later 135mm

The temperature is 21 degree Celsius, the curing time is more than 40 minutes, and the intensity only remains on the surface.
 
The surface layer shows intensity, but the middle layer is not, so the chance of bleeding is relatively high. Generally, it may be bleeding or delamination.

The amount of sulfoaluminate cement was a bit too high, and there was too much gypsum. Therefore, suspending agents is not recommended.

It is necessary to adjust the basic raw materials such as cement to solve the delamination problem instead of relying on additives; otherwise, it is elementary to cause problems.
 
The flocculation component in the formula is too high, and the stabilizer and cellulose ether need to reduce. If the temperature is 21°, you should also reduce the amount of retarded.
 
You have to ask the manufacturer for the specific composition of the suspension stabilizer. In addition, what is the testing intensity on the first day? Then, it is necessary to do a physical performance test. The formula fails if the intensity is lower than 8MPa on the first day. It includes 150kg sulfoaluminate cement + 10kg Redispersible Polymer powder. Is it for high-strength bedding mortar?
 
Choose either a Suspension stabilizer or Cellulose ether that will work. Reduce sulfoaluminate cement to 100 and Gypsum to 40; is it better?
 
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