Problems that tend to arise in the production and use of mortar
Problems arising from segregation of mixed mortar.
1) In the bulk mobile silo, the part of the mortar that is just discharged at the beginning and the part that is discharged at the end of the bulk mobile silo is prone to segregation.
Solution: Keep the amount of dry mortar in the bulk mobile silo at the construction site not less than 3 tonnes. In order to avoid the dry mortar in the process of hitting the bulk mobile silo, the height difference between the lower material is too large, resulting in segregation.
2) Dry mortar in storage tanks and transport vehicles is easy to segregate.
Solution: Store the dry mortar in the storage tank and transport vehicle as full as possible. Even speed, smooth transport.
3) loading and unloading speed is too slow so that the dry mortar is easy to segregate.
Whether it is loading, pumping material. Or storage tank material. Loading and discharging volume should be large. Speed should be fast. Experiments have shown that the amount of material is small, the material is slow than the amount of material is large, the material is fast dry mortar “segregation” phenomenon to be serious.
Solution: increase the aperture of the silo under the material mouth, accelerate the material speed.
4) bulk mobile silo below the mixer capacity is small. Mixed material volume is small. It is also the cause of slow discharging speed and poor mortar quality.
Solution: Consider modifying the mixer capacity under the bulk mobile silo or installing a large-capacity mixer.
Quality problems arising from the production of dry-mixed mortar.
1) The sand contains too much mud or the sand is too fine causing the dry mortar to crack.
Solution: Control the mud content and fineness of raw sand and try to use medium sand.
2) The ready-mixed mortar production unit did not adjust the mortar ratio at the right time with the changes of wall materials and temperature. This causes the mortar to crack.
Solution: according to different ambient temperatures, different wall materials and other conditions in a timely manner to adjust the production formula. Such as summer temperatures up to 30 ℃. When plastering on the wall of lightweight aggregate blocks. Need the water retention rate of the mortar to be higher. The amount of additives mixed in the mortar should be adjusted appropriately to improve the water retention rate of the mortar.
Construction unit operation is not standardized.
1) The one-time plastering is too thick during construction, resulting in cracking of the mortar.
Solution: according to the standard construction operation, one-time plastering is not too thick. If the specification of thickness of external wall plaster requires that the thickness of each layer should be 5~7mm each time. when the total thickness of plaster is more than 35mm, strengthening measures should be taken. Strengthening measures should be taken.
2) The mortar is applied on the substrate or grass-roots level that is not compatible with its strength grade. The mortar shrinkage is inconsistent with the grassroots level resulting in cracking of dry-mixed mortar.
Solution: Use mortar of appropriate strength grade for various wall materials respectively.
3) Not taking measures at the junction of different materials, resulting in cracking of dry-mixed plastering mortar.
Solution: The junction of different materials should be treated with reinforcing net.
4) The masonry is not sprinkled or sprinkled with too much water, resulting in cracks and fissures in the dry-mix plastering mortar.
Solution: According to the standard construction operation. Such as for sintered bricks, autoclaved fly ash bricks plastered before watering and wetting.
5) autoclaved bricks and other masonry has not reached the age of masonry, plastering construction, resulting in cracking of dry plastering mortar.
Solution: All kinds of block materials need to reach the required age, to be used only after its volume stability. Such as autoclaved bricks should not be used before the age of less than 28 days.
6) dry mix plastering mortar and dry mixing ground mortar is not timely moisturising maintenance after condensation. Caused by mortar dry shrinkage cracking.
Solution: After the mortar is set, moisturise and maintain it in time.
7) Mixing other materials at the construction site. Such as mortar king, sand, lime, etc., resulting in a reduction in mortar strength. Even flaking and cracking.
Solution: The construction site without the permission of the mortar manufacturer is prohibited to mix other materials into the mortar.