4.2.1. Introduction to technology.
Mechanical spraying plastering is to pour the ready-mixed mortar into the mortar transfer pump, through the pipeline, and then with the help of the pressure of the air compressor, the mortar is continuously and evenly sprayed on the wall and ceiling, and then leveled and compacted to complete the plastering finish.
This method avoids the traditional way of using bucket truck and vertical transportation machinery to transport mortar to the working face, reduces the landing ash in the mortar transportation process, reduces material loss, and the labor efficiency of mechanical plastering is greatly improved, and the work efficiency is more than 2 times that of manual plastering, shortens the construction time, accelerates the progress, saves costs and ensures the safe and civilized construction of the site. In the process of mechanized construction, the operation performance is good, the cloth is uniform when spraying, and the pressure of spraying is generally 0More than 5MPa, high pressure, strong adhesion, firm bonding, no hollowing, cracks and peeling, high degree of tightness, not easy to fall off, to ensure the molding quality of plastering.
4.2.2 technical points.
The ready-mixed mortar is poured into the mortar pump, through the pipeline, and then with the help of the pressure of the air compressor, the mortar is continuously and evenly sprayed on the wall and ceiling, and then leveled and compacted to complete the plastering finish.
Figure 42.2-1 Schematic diagram of mechanical spraying.
The inner diameter of the slurry pipeline for mechanical spraying and plastering should be selected in the following table, and when the fineness modulus of the mortar sand is large or contains fibers, the pipe diameter should be larger.
Table 42.2-1 Selection of the inner diameter of the slurry pipe.
When the mortar pumping stops in the middle, it is easy to block the pipe, so it is advisable to operate continuously. Minimize the number of pumping interruptions during construction, and if there are frequent interruptions, the construction arrangement should be adjusted. In the process of working of the transfer pump, the working pressure will fluctuate with the change of mortar fluidity, conveying distance and pipeline condition, the operator should pay attention to observe the pressure change indicated by the pressure gauge at any time, if the gauge pressure suddenly rises to more than the maximum pressure, and the safety device does not act, the unloading valve should be opened immediately to relieve the pressure, and stop the machine to check and eliminate the fault before resuming work. The normal working pressure is shown in the table below
Table 42.2-2 Pressure reference value during pumping.
4.2.2. Economic and social benefits.
This technology is suitable for the mechanical spraying plastering construction of the wall column surface, floor and general building surface of multi-storey and high-rise buildings, because the mechanical spraying plastering has obvious effect on reducing labor intensity, improving construction efficiency and ensuring construction quality, so it has obvious economic and social benefits.