The advent of the shotcrete machine added new machines to the construction industry and made a great contribution to the society. Today's shotcrete machines are very different from traditional shotcrete machines, especially in the process of operation, Traditional shotcrete machines require multiple people to operate in the process of operation, and today's shotcrete machines require only one person to complete the work, which not only saves manpower but also saves a lot of materials. However, during the operation of the shotcrete machine, high requirements are placed on the concrete.
Before the shotcrete machine is started, the old tape must be laid on the spraying site in order to collect the rebound material. The rebound rate must not exceed 15%. The shot sequence of the shotcrete machine should be the wall first and the arch from the bottom of the wall. During the process, the spray gun head and the sprayed surface should be kept as vertical as possible, and the vertical distance between the spray gun head and the sprayed surface is 0.8M-1.0M. Use tide mix for manual mixing. Cement, sand and stones should be mixed and turned 3 times to make it mix well. When spraying the spray gun, the spray pressure of the spray gun is 0.4MPA, and the water pressure should be about 0.1MPA higher than the wind pressure. The amount of water added is controlled by the shooter's experience, and the water-cement ratio is 0.4-0.5. During the spraying process of the shotcrete machine, the water supply should be adjusted in time according to the changes in the discharge to ensure the accurate water-cement ratio. The sprayed wet concrete should have no dry spots, no flow, strong adhesion and less rebound material. The thickness of one shot of concrete is 50-70MM, and it is necessary to re-spray in time. The interval between re-spraying must not exceed 2 hours, otherwise the high-pressure water should be used to flush the sprayed surface again. After the spraying machine finishes spraying, the spraying layer must be continuously sprayed for more than 28 days, and sprayed once per shift within 7 days. Once the spraying is completed, the projectiles should be packed up immediately, and the mixing on the shift should be cleaned up.
