From an initial formula, record every change, and finally adjust to standard self-leveling formula.

[Shamil]

Initial data:

425 cement: 320, sulpho-aluminous cement: 60, hemihydrate gypsum: 7.4

Ash calcium: 7.4, coarse whiting: 128, Sand: 463, Polycarboxylic acid: 0.6

Tartaric acid: 0.32, Glucose: 0.4, Early strength agent: 0.8

Defoaming agent: 0.8, Cellulose ether: 1.28, Redispersible polymer powder: 11.12

The initial fluidity is 133, and after 10 minutes, it is 117. The fluidity loss is a bit large (add some retarder), the water collection time is 38 minutes (it is reasonable in summer, but I am afraid it will be longer if the retarder is added), and cracks appear on the glass after ten minutes. That’s it for now; I’ll update the strength of the sample on the glass the next day.

 

[Cassie]

Cement 320 should reduce 50 kilograms. Gypsum is too small, add it to 40 kilograms.
No need for early strength agent.

 

[Shamil]

Cement 320 should reduce 50 kilograms. Gypsum is too small, add it to 40 kilograms.
No need for early strength agent.

If the 425 cement is reduced, will the strength drop? There is too much sand, so I am worried. Also, what is used is not high alumina cement but sulfaluminum cement. You don’t need too much gypsum. What do you think?

 

[Cassie]

If the 425 cement is reduced, will the strength drop? There is too much sand, so I am worried. Also, what is used is not high alumina cement but sulfaluminum cement. You don’t need too much gypsum. What do you think?

I also used sulfaluminum cement.

 

[Shamil]

I also used sulfaluminum cement.

425 cement: 320

sulfaluminum cement: 60

Semi-hydrated gypsum: 20 (original 7.4)

Ash calcium: 7.4

coarse whiting: 128

Sand: 450 (formerly 463)

Other additives remain unchanged

Problems with the formula: 1. The surface layer is firm. If this layer is scratched, the sand inside is weaker (no sand settling). 2. It dries a bit slowly. It took 13 hours for the sample to turn completely white.

 

[Cassie]

425 cement: 320

sulfaluminum cement: 60

Semi-hydrated gypsum: 20 (original 7.4)

Ash calcium: 7.4

coarse whiting: 128

Sand: 450 (formerly 463)

Other additives remain unchanged

Problems with the formula: 1. The surface layer is firm. If this layer is scratched, the sand inside is weaker (no sand settling). 2. It dries a bit slowly. It took 13 hours for the sample to turn completely white.

1. It dries too slowly, and the amount of retarder you put in needs to be more significant. Usually, more than this amount may be needed, so your sulfalumina cement should be stale, left for a long time, or from a small factory.

2. The surface layer has strength. This is relatively common. It has something to do with your strength. It may also be slightly hindered by water bleeding on the surface. As for the sand layer, it cannot be seen in the leveling. It needs to pour the slurry into a transparent plastic cup and observe the shrinkage and delamination 24 hours ago (homemade method)

Regarding the retarder, generally, as long as it can meet the fluidity for 20 minutes to half an hour, no more can be added. There is no need for a surplus; otherwise, the strength index level will decrease.

 

[Rony]

Just a few simple suggestions:

1. The cementing material of the entire system is essential, so it is best to use large manufacturers of sulfaluminum cement, ordinary Portland cement, and gypsum. Generally, the selectivity of ordinary silicon is small. You can choose several companies for sulfaluminum cement;

2. Adjust the construction performance first, then consider strength, shrinkage, and apparent condition. After all, you have just started to do it. If you only look at the construction performance, you can do many experiments in one day to save time;

3. Besides single-factor comparative experiments, orthogonal and uniform experimental systems can be used for comparative tests, making the results easier to trace and analyze.

 

[Ankur]

This kind of experiment must consider the impact of other factors on the data.

Such as glass processing methods, temperature and humidity considerations, purity and stability of raw materials.