混凝土喷射机具有机械化程度高的优点, 工艺简单，生产效率高. 广泛应用于建筑中地下及地面混凝土工程, 市级, 铁路, 采矿业和其他行业. 已在许多国家得到广泛应用，并显示出良好的技术和经济效益.
According to 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 being evenly mixed, it is blown to the nozzle by compressed air, mixed with pressurized water from the pressure water tank, and then ejected. The construction method in this way 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. Entering the jet is a concrete mix that has been added with water. 所以, 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 tank and the pipeline, causing troubles of clogging and cleaning, and thus has not been promoted.
The quality of concrete jets has a lot to do with the mix ratio of the mix. The specific requirements are:
1. 水泥. Grade 32.5 Portland cement should be used;
2. 总计的. Should be sieved before use, its maximum particle size should not exceed 20mm; its moisture content should be controlled within 5% to 8% (volume fraction);
3. Accelerator. The blending amount is 3% to 4% of the mass of the cement and should be added before spraying;
4. Mixing ratio of concrete mix. 水泥: Sand: Stone = 1:2:2 ~ 1:2: 2.5 is better.
