The reasons are as follows:
1. After finishing the cover, the mortar does not receive water and begins to press. After it is pressed, it produces blistering.
2. The lime paste is not ripe, and the ash is not filtered. After being plastered, the lime granules which are not completely cooked will continue to mature, and the volume will expand, causing surface pitting and flowering.
3. When the base ash is too dry, the moisture will be absorbed quickly by the bottom when the cover is covered with ash.
Prevention and control measures:
1. Until the plaster mortar is collected, it will be calendering before final condensation; when the paper reinforcement is covered with lime, it must wait for five or six of the ash to dry.
2. The curing time of lime paste is not less than 15d. When the ash is used, the sieve is less than 3mm * 3mm. When using the fine lime powder, it is best to turn 2D to 3D into lime paste in advance.
(3) for the already blooming wall, the normally treated and non slaked lime granules are completely cured before expansion. The method is to remove the loose surface on the blooming area, then use the putty to scrape the flat and then spray.
The bottom should be watered and moistened, and then a thin layer of pure cement will be used to cover the surface. When the cover is pressed, it is found that when the surface layer is too dry and not easy to press, it should be sprinkled and pressed again to prevent spreading.