Can anybody offer an guidance for the anti-cracking mortar formula?

[Alex]

42.5 Cement:400kg, sand 40-70:600KG, cellulose 200,000 viscosity: 2KG, Redispersible Polymer powder:5.5kg, the cost is cheaper compare others on the market. After 30 hours on the wall, rub it with hands and there is a slight white. Can anybody offer a solution?

 

[Rony]

The water retention of cellulose is not enough, you should add some 2488.

 

[Cassie]

The related factors affecting the crack resistance are mainly the mortar folding ratio and interface cohesion. There are fibers, redispersible polymer powder, and high-grade glue materials to improve the flexural resistance of the mortar, and the only way to improve the cohesive force is to add more redispersible polymer powder.

I recommend to add a tiny amount of 3mm fiber.

 

[Ramon Doria]

The water retention of cellulose is not enough, you should add some 2488.

What is 2488?

 

[Ankur]

I suggest you add some cellulose ether and sulpho-aluminous cement. The formula, the simpler, the better. And the amount of cement can decrease to 350.

 

[Rony]

What is 2488?

2488 is polyvinyl alcohol powder.

 

[Scott Kaplan]

The amount of cement is high, and the cellulose is low.