At present, there is no unified specification and standard for the surface treatment process of high-speed rail box girder beams. The construction techniques of various bureaus of China Railway are also varied, and a unified technical specification has not yet been formed.
At present, the process of some high-speed railway project departments is as follows:
1. The superelevation part of prefabricated beams and cast-in-place beams can first find out the approximate area with a ruler, and mark the error value with chalk or paint.
2. Use a small milling machine to carry out rough grinding within the designated range. Electric gasoline milling machines can be used, depending on the power supply conditions on site.
The small milling machine can mill (grind) the beam surface about 3-5mm at a time, and it can grind 1-2cm down after repeated milling.
Of course, for the beam surface with too much elevation error, you can buy a larger milling machine with a milling depth of about 10mm at a time.
3. After the rough grinding of the milling machine, measure the elevation, if the depth is not enough, continue milling.
4. After the elevation measurement is qualified, use a grinder for fine grinding and finishing.
Other brother units use shot blasting machines for processing, but the construction cost of shot blasting machines is higher, and the efficiency is not necessarily faster than milling machines, but the surface after processing is smoother, but it is still pockmarked. Grinding machinery is required.
The processing effect of the chisel machine is similar to that of the milling machine, but because the chisel head hits the beam surface vertically, it is easy to damage the internal structure of the cement concrete, and it needs an external air compressor and air pipe, so the operation is not as convenient as the milling machine. The work efficiency is not as high as that of the milling machine.
It is worth noting that there are many small milling machines because of their light weight, small number of blades, and low power, so the milling effect is similar to that of a grinder.
