There are not only many types of construction mortar, but also many requirements before and after construction. Landcel introduces you to the professional knowledge about construction mortar.

1. What are the raw materials of wet-mixed mortar?

Answer: Wet-mixed mortar is mainly composed of sand, cement, admixtures (fly ash, stone powder, etc.), admixtures, and water.
Compared with concrete, there are fewer stones. But the requirements for raw materials are different, especially sand and admixtures. The sand fineness modulus of the wet-mixed mortar is required. The admixture is completely different from the concrete admixture, and the composition is very different.

2. What are the types and models of wet-mixed mortar?

Answer:Divided into masonry mortar, plastering mortar, ground mortar and so on.

3. What is masonry mortar?

Answer:Mortar used for masonry bricks, stones, blocks and other massive building materials. Masonry mortar can be used to bond all kinds of bricks. Red clay brick with low water absorption. Lime-sand brick with strong water absorption and aerated lightweight concrete brick. It plays the role of building masonry and transferring loads. It is an important part of masonry.

1) What is plastering mortar? Mortar applied to the surface of a building or the surface of a building to be applied to a wall at a specified thickness. Plastering wet-mixed mortar requires good workability, easy to plaster into a uniform and flat thin layer, easy to construct, and has high cohesive force.
2) Can the concrete production line make wet-mixed mortar?
Answer: Yes, the concrete production line can be used for special line production of wet-mixed mortar after minor adjustments, and can also be produced in-line with concrete. The national standard GB/T25181-2019 stipulates that the wet-mixed mortar should be mixed with a fixed mixer required by GB/T9142, and the gap between the mixer blade and the liner should be less than 5mm. An independent production line should be adopted. But a high-efficiency sand screening machine must be used. A plasticizer tank with a capacity of at least 10 tons.

4. What are the types of mortar cracking?

Answer: Mortar is divided into plastic cracking, drying shrinkage cracking, and mortar cracking.

5. What are the reasons for the plastic cracking of mortar and how to deal with it?

Answer: The thickness of the mortar layer is uneven and the local area is too thick, causing plastic cracking due to falling. Due to the non-standard flatness of the base layer of the wall, the uneven thickness of the plastering is caused. During the construction, the falling mortar should be leveled and compacted in time. It is recommended that the workers perform multiple times of plastering and use anti-cracking mesh.

6. Reasons and treatment of mortar shrinkage and cracking?

Answer: The high mud content of the sand, excessive mixing of fine sand, and rapid water loss due to weather during construction, etc., cause shrinkage cracks.
To deal with drying shrinkage cracks, it is first necessary to strictly control the mud content of the sand within 5%, and at the same time prevent workers from using tailing slurry and overnight ash.

7. What are the reasons for mortar cracking and how to deal with it?

Answer: The ratio of mortar to glue is too low, the strength is too high, and the shrinkage rate is too large, causing cracks in the mortar.
For mortar cracking, the ratio of mortar to sand should be controlled, and the strength of mortar used should not be too high if sand accounts for 70%-80% of the total dry material.

8. What are the types of mortar hollowing?

Answer: Mortar hollowing is divided into shrinkage hollowing and constructional hollowing.

9. What are the reasons for the shrinkage and hollowing of mortar?

Answer: Shrinkage hollowing is mainly because the bonding force between the interface layer and the base layer is smaller than the shrinkage stress between the mortar and the interface layer. The main reasons are: irregular base treatment, poor interface mortar adhesion, and excessive mortar shrinkage.

10. How to avoid shrinkage hollowing of mortar?

Answer:To avoid shrinkage hollowing, the adhesive force of the interface mortar should be improved to ensure that the adhesive force of the interface mortar is higher than that of the plastering mortar.
The strength level of the interface mortar is higher than that of the plastering mortar, and the interface treatment of the base layer should be done well.