Surface coating crack-resistant mortar and thermal insulation waterproof mortar; the causes of cracking include the following aspects:
The gel powder lacks flexibility, (it is rigid).
2. The cement mix ratio was not reasonable, resulting in excessive cement usage.
The sand used was too fine, which failed to provide crack resistance, especially during the summer when temperatures are high and moisture evaporates quickly. As the cement loses water, it contracts rapidly, forming cracking patterns.
Recommend using medium sand20-40Objective, fine sand40-80The blend of coarse and fine sand, in a ratio of two to one, offers excellent crack resistance. The coarse sand minimizes shrinkage by filling fewer voids between the mud and coarse sand, thereby providing a good anti-cracking effect.
Silicate cement 42.5# boasts high compressive strength and a slightly faster setting time, but its drawback is that it has greater shrinkage than 32.5#. When in use, it is advisable to increase the amount of sand appropriately.
Cement final strength28 days(Pasteurization)
