The precaution of the wet shotcrete machine during the construction of the slope

In recent years, wet-jet spray concrete technology with its simple technology, unique effects, economic cost, and wide range of uses in a variety of construction areas shown strong vitality. Wet shotcrete machine is widely used in slope construction, so what are the precautions in the construction of the slope?

1. Wet spray jet operation, should be strictly controlled water-cement ratio and quick-setting agent dosage, after spraying, so that the spray surface is smooth, with no dry spots or slip flow phenomenon;

2. Wet spray jet should be sub-section, sub-section, block, according to the first wall after the arch, from bottom to top. The length of the segment does not exceed 6m, the division is the first after the next, the block size of 2m × 2m, so as to reduce the role of concrete due to gravity caused by sliding or shedding phenomenon;

3. Wet shotcrete machine spray concrete, which can move forward by spiral, can also be used to move forward S-shaped forward;

4. Control the distance and angle of the nozzle and the spray surface, the distance is 0.8 ~ 1.2m is appropriate, too large or too small will increase the amount of rebound, the nozzle, and the spray surface is vertical and slightly biased to just spray the site (tilt Angle should not be greater than 100), the rebound is the smallest, the best spray. The rock surface depression should be sprayed and sprayed, and the protruding should be sprayed or sprayed less;

5. Adjust the wind pressure, and water pressure, wind pressure is too large to increase the amount of rebound, too small is the poor density of concrete;

6. Spray operation should be layered, a jet is too thick, will cause expansion, affecting the adhesion of concrete and cohesion, likely to cause separation or due to self-weight and the occurrence of large cracks caused by slump; Aggregate is not suitable for bonding, increase the amount of spring; therefore, a jet is too thick or too thin on the jet quality have an impact, but the initial spray thickness of not less than 4 ~ 6cm;

7. Wet shotcrete machine after the completion of the concrete injection, the jet and the delivery of the material must be promptly removed clean;

8. Wet shotcrete machine Shot concrete operation must follow the excavation surface, and the next blasting and spray concrete working surface completion time interval of not less than 4h.

The principle of wet shotcrete machine spraying concrete is to mix the aggregate, cement, and water according to the design ratio, with a wet jet mixer to mix the concrete mixture to the nozzle, and then fill the nozzle in the quick-setting agent after the spray. Wet spray concrete quality is easier to control, spray the process of dust and rebound less.