Concrete Shotcrete Classification

Concrete shotcrete machine is widely used in tunnels, culverts, subways, bridges, coal mines, high-moisture mines, hydropower projects, underground engineering, construction engineering and other protective engineering machines. According to different classification standards, there are different classifications. Today we mainly introduce the following classifications:

A. According to the different methods of adding water to concrete mix, it can be divided into dry type, wet type and semi-wet type between the two.

1. Dry type According to a certain proportion of cement and aggregate, after mixing evenly, it is blown by compressed air and sent to the nozzle and pressurized water from the pressure tank to be sprayed out. In this way, the construction method is simple and the speed is fast, but the dust is too large, the amount of rebound of the spray material is large, and high-grade cement is used. Most of the domestic production is dry.

2. Wet type The concrete mixture that has been added to the jet is filled with water. Therefore, the dust content in the injection is low, and the amount of rebound is also reduced, which is an ideal injection method. However, the wet material tends to condense in the material line, causing clogging and troublesome cleaning, and thus has not been promoted.

3. Semi-wet type is also called tide type, that is, concrete mix is damp material (by volume) with water content of 5%~8%. When this material is sprayed, dust is reduced, because it is less adhesive than wet material, non-sticky. Cans are an improved way of dry and wet.

B. According to the structure of the jet machine, it can be divided into three types: cylinder type, spiral type and rotor type.

1. Cylinder tank type Cylinder tank type shotcrete machine is sturdy and durable. However, the body is too heavy, and the opening and closing of the upper and lower bell valves requires manual heavy operation, labor intensity, and easy to block the pipe, so it has been gradually eliminated.

2. Spiral type Spiral jet machine has simple structure, small volume, small mass and good maneuverability. However, when the conveying distance exceeds 30 m, it is easy to return air, and the productivity is low and unstable, and it is only suitable for the spray support of small roadways.

3. Rotor type rotor jet machine has the advantages of large production capacity, long conveying distance, continuous and stable discharging, low feeding height, convenient operation, suitable for mechanized supporting operations, etc., and can be used for dry spray, semi-wet spray and wet spray. A variety of spray methods, is a widely used model.