How to reduce rebound and dust when spraying concrete? When spraying concrete, the following measures can be taken to reduce rebound and dust:

　　Measures to reduce rebound:

　　1. Optimize the mix ratio: Use a reasonable mix ratio of cement, aggregate, water and admixtures to improve the cohesion and sprayability of concrete.

　　2. Control the spray distance and angle: The distance between the nozzle and the sprayed surface should be 0.6-1.2 meters, and the spray angle should be as perpendicular to the sprayed surface as possible.

　　3. Appropriate wind pressure and water pressure: According to the performance of the sprayer and the transportation distance of the concrete, adjust the appropriate wind pressure and water pressure. Generally, the wind pressure is controlled between 0.1-0.15MPa.

　　4. Layered spraying: The layer thickness should not be too large, generally 5-10 cm. Layered spraying can make the concrete adhere better to the sprayed surface.

　　5. Strengthen operator training: Improve the technical level and experience of operators so that they can master the spraying skills.

　　Measures to reduce dust:

　　1. Strengthen ventilation: Set up good ventilation equipment in the spraying operation area to discharge dust in time.

　　2. Wet spraying process: The wet spraying concrete process can significantly reduce the generation of dust.

　　3. Control the spraying speed: Avoid too fast spraying speed to reduce the dust generated by the friction between concrete and air.

　　4. Install water rings on the nozzles: Install water rings at the nozzles to suppress dust flying by spraying water.

　　5. Wear protective equipment: Construction workers wear effective dust masks, goggles and other protective equipment.

　　6. Humidification of raw materials: Appropriately humidify the aggregates before mixing to reduce the generation of dust.