Self-leveling cement formula, bleeding, sedimentation, could you please give me advice on the formula?

Alex

Alex

Moderator
Ordinary Portland cement 260, aluminum sulfate 100, anhydrite 55, sand 70-140 430, Heavy calcium carbonate 130, redispersible polymer powder 12, polycarboxylate superplasticizer 10, p803 1.5, hpmc400 0.1, sodium phosphate anhydrous 1.5, tartaric acid 0.4, sodium glucosamine 0.4, Water 280, initial flow 130

After 20 minutes, the sedimentation was severe and there is bleeding. I didn’t measure the flow. Please give me some advice.
 
Is this a polycarboxylic acid superplasticizer? If you add so much, do you need to add 280kg with water? Add a little hpmc, drop the water a little, and add a little retarder appropriately.
 
Sodium gluconate/anhydrous sodium sulfate is not needed. You can use Polycarboxylic acid water-reducing agents but use the maximum amount carefully. More than 1 kg may be required.

The cellulose ether 0.1 kg is less; it should be around 0.5~1.0

The amount of aluminum sulfate is about 100, which can be adjusted. It can be less. It will be fine if the strength reaches the standard within 24 hours.

Retarder dosage + tartaric acid is better, sodium citrate is not good, and sodium gluconate is ineffective in aluminum sulfate.
 
Bleeding should first consider three aspects:

1. Too many admixtures are added;

2. Added too much water;

3. The cellulose ether was added too little.

I saw that you wrote several formulas, but I needed to see data on fluidity. Is it because the bleeding was not measured? You must adjust the initial state first and then look at other things. If you keep doing it, this experiment will be easy. If the fluidity is very small, it will still bleed. Then, it would help to consider whether there is a problem with the cement, such as the addition of coal gangue, high loss on ignition, etc. What is the sand gradation like?
 
I have adjust my formula a bit, please take a look and give me some feedback

Ordinary Portland cement 260, aluminum sulfate 90, anhydrite 50, sand 70-140 450, Heavy calcium carbonate 130, redispersible polymer powder 15, polycarboxylate superplasticizer 2, p803 0.5, cellulose ether 0.8, sodium phosphate anhydrous 1.5, tartaric acid 0.8, sodium glucosamine 0.2, water 260.
 
Alex said:
I have adjust my formula a bit, please take a look and give me some feedback

Ordinary Portland cement 260, aluminum sulfate 90, anhydrite 50, sand 70-140 450, Heavy calcium carbonate 130, redispersible polymer powder 15, polycarboxylate superplasticizer 2, p803 0.5, cellulose ether 0.8, sodium phosphate anhydrous 1.5, tartaric acid 0.8, sodium glucosamine 0.2, water 260.
Click to expand...
Lower water reducing agent and more cellulose ether can significantly improve the effect.
 
The principle of bleeding is straightforward; that is, you add too much water than the water required for cement.

For 415% of the binder, add 280% of water, which is too much. Is it strange that the cement contains fine powder with a total heavy calcium carbonate content 545, 1% water-reducing agent, and 28% water? The fluidity is only 130.

There is something wrong with your water-reducing agent. Try changing it to a bigger brand with better quality.
 
Is the amount of water-reducing agent written wrong? Usually, add 1.0-1.5 for polycarboxylic acid. There is less cellulose ether, more water-reducing agent, and low viscosity will inevitably lead to bleeding and settling.
 
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