What are the requirements for grouting media and process flow during the use of grouting pump?
The use of grouting pumps requires strict requirements for grouting media and the correct process flow to ensure successful grouting. For grouting pump requirements on grouting media and process flow, please refer to the following aspects.
First, the grouting pump requires the grouting medium
1. Use high quality Portland cement as the medium;
2. The fineness modulus of medium sand or coarse sand should be greater than 2.5, and the mud content should not exceed 3%;
3. When using water glass as the grouting medium, the particle size of the medium should be no more than 15mm;
4. When using alkaline accelerator, the medium should not be doped with active silica;
5, the medium can not contain too much impurities, the water content is controlled at 10% to 15%;
6. The initial setting time of the accelerator should not exceed 5 minutes, and the final setting time should not exceed 10 minutes.
Second, the grout pump requires process flow
1. Before the grouting pump is working, first place the old tape at the grouting place to collect the rebound material, and the rebound rate requirement must not exceed 15%;
2. The grouting sequence of the grouting pump should be first and then the outer, first and second, and the spray head and the grouting surface should be kept as vertical as possible. The vertical distance between the spray head and the sprayed surface is required to be 0.8M-1.0M;
3. When the grouting pump grouts, the grouting pressure is 0.4MPA, the water pressure should be about 0.1MPA higher than the wind pressure, and the water addition amount is controlled by the experience of the shooter, the water-cement ratio is 0.4-0.5;
4. During the grouting process of the grouting pump, according to the change of discharge, timely adjust the water supply to ensure the water-cement ratio is accurate, and the grouting medium is required to have no dry spots, no runny, strong adhesion, and less rebound material;
5. Re-injection is required in time after the completion of grouting. The interval between re-spraying shall not exceed 2 hours, otherwise the high-pressure water shall be used to re-rinse the surface to be sprayed;
6. After the grouting is finished, the rebound medium is required to be recycled in time, and the mix is used on the shift.