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Sprayed concrete is a kind of concrete that is solidified and hardened by spraying mixed materials in a certain proportion by means of machinery, compressed air or other power, through a pipeline pump at high speed on the sprayed surface. There are usually two ways to spray concrete, namely dry spraying and wet spraying.
Wet shotcrete is a method in which a shotcrete machine is used to press and feed the wet mixture, and the quick-setting agent is added to the nozzle, and then sprayed onto the structural surface. With its unique advantages, wet sprayed concrete has been used more and more widely in construction.
Compared with dry mix shotcrete, the obvious advantage of wet spray is high productivity.
Wet spraying can greatly reduce the rebound, and the average rebound is ≤20%, ensuring the construction quality.
The thickness of one spray layer of wet sprayed concrete is greatly increased than that of dry spray, which can reduce the number of spraying to reach the thickness of the designed spray layer, simplify the process, and increase the construction speed.
In recent years, wet spraying machines have gradually become the mainstream equipment in the support industry. The hydraulic wet spraying machine is pumping type concrete wet shotcrete machine. It adopts hydraulic pumping type and has high construction efficiency. The shotcrete amount and the addition amount of accelerator can be adjusted. It can be used for spraying, filling, grouting, pumping and other constructions.
The Gengli hydraulic wet shotcrete machine is using the thrust of the hydraulic pump to make the two cylinder reciprocating, the dense flow material will be sent to the mixing pipe by conveying pipe, it becomes thin flow by compressed air, then through the pipe to the nozzle. Add a certain proportion of the accelerator to the nozzle then spray directly to the surface. The hydraulic wet spraying machine is widely used in construction of highway, railway, tunnel and hydropower station etc.
1. Stable performance, less wearing parts and low maintenance cost
2. Throughput can be adjusted as needed
3. The electrical appliance adopts PLC centralized control, reliable work, long life, easy operation
4. Continuous spraying with less pulse
5. Continuous and adjustable feeding for accelerator
The use of the shotcrete machine is very extensive. The main applications are in roadways, subways, tunnels, hydropower projects, culverts, underground projects, protection projects, etc.
According to the different methods of adding water to the concrete mixture, shotcrete machine can be divided into three types: dry shotcrete machine, wet shotcrete machine and semi-wet type shotcrete machine.
Dry mix shotcrete is a method of mixing cement, sand and stones in a dry state, and then sending the material to the nozzle with compressed air, and spraying after mixing with water. Dry spray method using a dry mix shotcrete machine.
Features of Gengli dry shotcrete machine:
Gengli machinery is an expert shotcrete machine supplier with large product line, including dry shotcrete machine and wet shotcrete machine, etc.
Concrete shotcrete machine is a machine that uses compressed air to continuously transport concrete along the pipeline and spray it onto the construction surface. Concrete spraying machines are divided into dry spraying machines and wet spraying machines. The former is pneumatically conveyed dry-mixed material, mixed with pressure water at the nozzle, and then sprayed out; the latter is delivered by pneumatic or concrete pumps and the concrete mixture is sprayed out through the nozzle.
Shotcrete machine is a kind of equipment that is widely used in tunnels, culverts, subways, water conservancy projects, and underground works shotcrete construction operations. Shotcrete machine can be used as well for small jobs, such as joint filling, swimming pool, refractory application and extensive slope consolidation work, etc.
The Gengli shotcrete range guarantees uniform material flow, virtually dust-free processing and high performance.
The quality of our gunite machine is guaranteed and can make users feel securely in the use process. If you are interested in our products, welcome to contact us.
Shotcrete machine is a kind of equipment that is widely used in tunnels, culverts, subways, water conservancy projects, and underground works shotcrete construction operations. Shotcrete machine can be used as well for small jobs, such as joint filling, swimming pool, refractory application and extensive slope consolidation work, etc. There are usually two types of shotcreting machines: dry spraying machines and wet spraying machines.
The dry mix shotcrete machine requires that the sprayed concrete, cement and other materials added into the hopper are dry. The air compressor exerts pressure to send the dry materials to the sprinkler head where there is an inlet pipe. Then the material is mixed with water at the shotcrete nozzle and then ejected.
Wet mix shotcrete machine is a kind of bolting and shotcrete supporting machine with good comprehensive performance such as reducing dust, reducing spring back, and saving materials. It uses compressed air or other power to transport a certain proportion of the mixing material through the pipeline and high-speed injection to the sprayed surface to form a concrete supporting layer.
Compared with dry shotcrete machine, wet shotcrete machine has low dust concentration, low rebound rate and accurate control of water-cement ratio. It can fully hydrate the cement and has high strength of sprayed concrete, greatly saving cost and is suitable for various working environments.
Shotcrete has become a common practice for both new construction and repair and renovation. Concrete can be sprayed by one of two processes – one is “dry shotcrete” or “gunite” in which case dry material floats to the end of the hose via compressed air, then water is added at the nozzle. The second process “wet shotcrete” is the process whereby the material is mixed with water, added to the pump, then conveyed in a wet slug through the pipeline until it reaches the nozzle where air is then added to give the material velocity so it will stick to the wall or overhead.
The difference between dry and wet shotcrete:
Dry sprayed concrete mixes cement, sand, stone mixture and powdered accelerator in a certain proportion and mixes them evenly. In a loose, dry and suspended state, dry shotcrete machine is used and compressed air is used as power, through the feeding tube to the nozzle, mixed with a certain amount of pressure water, and it becomes concrete with a relatively small water ash and sprayed onto the sprayed surface. If a special quick-setting anchor is used for spraying cement, the accelerator may not be used. The process is simple, easy to operate, and has a long conveying distance (up to 150-200m on average), but the large dust and high rebound rate are its fatal weaknesses.
Wet spraying is a new sprayed concrete technology developed for the problems of dry spraying, such as large dust, large rebound rate, and insufficient hydration. The obvious feature of wet shotcrete is that the concrete mixture is added with sufficient mixing water before entering the shotcrete machine or in the jetting machine, mixed evenly, and then sent to the nozzle through the feeding hose to be sprayed onto the sprayed surface. Therefore, the water-cement ratio of concrete can be accurately controlled, which is beneficial to the hydration of water and cement. Therefore, the dust is small, the rebound is less, the homogeneity of the concrete is good, and the strength is easy to ensure, but the water consumption is greater than that of dry spraying. Compared with dry shotcrete machine, it is more complicated and costly. Wet shotcrete machine is the main equipment for wet spraying.
Gengli machinery is the excellent manufacturer of shotcrete machine with more than twenty years of production experience. The products include dry mix shotcrete machine, wet mix shotcrete machine, Truck-mounted Shotcrete Machine and Truck-mounted Robot Shotcrete Machine. If you are interested in our shotcrete machine, please contact us freely.
Shotcrete is a fast and effective reinforcement method that has evolved from roadway support technology to the reinforcement of above-ground structures. It has its own unique advantages: Shotcrete uses a shotcrete machine and compressed air as power to transport a certain proportion of the mixture through a high-pressure pipeline and spray it onto the sprayed surface at a high speed.
The spraying speed of concrete from the nozzle can reach 60m~80m/s. It depends on the repeated and continuous impact of cement and aggregate during high-speed spraying to compact the concrete. Due to the small water-cement ratio (0.4-0.5), it has high bonding strength with concrete, masonry, and steel. It can be used in combination with steel mesh to transfer tensile stress and shear stress on the bonding surface. Higher mechanical properties and good durability can greatly improve the bearing capacity of the masonry and strengthen the integrity. At the same time, the mortar can enter the reinforced pores and cracks under the high-speed concrete spraying state, so that the original structure can be restored to a certain extent.
It is suitable for masonry wall cracking reinforcement, brick and concrete structure layer wall reinforcement, seismic reinforcement, accident treatment and other projects.
Gengli is a professional shotcrete machine manufacturer.The shotcrete machines include electric shotcrete machine and Diesel shotcrete machine.
Applicable conditions of shotcrete slope protection：
1. For rock slopes that are hard and easy to weather, but have not been severely weathered, in order to prevent further weathering, spalling and sporadic chipping, shotcrete machine is used to spray concrete to form a protective layer on the slope.
2. It can be used on high and steep slopes, especially for slopes where the upper rock layer is broken and the lower rock layer is intact, and slopes that require large-area protection and are more concentrated. It is more economical to use shotcrete or shotcrete protection.
3.It is not suitable for claystone slopes with poor diagenesis.
4.It is suitable for dry slopes where groundwater is not developed.
Gengli is a professional manufacturer of shotcrete machine products. The products include dry shotcrete machine, wet shotcrete machine, Truck-mounted Shotcrete Machine and Truck-mounted Robot Shotcrete Machine. The Gengli machinery more than 26 years has specialized in production of shotcrete equipment. If you are considering a shotcrete machine that will provide longstanding value, allow Gengli to select the right model for your requirements.
Concrete shotcrete machine is a machine that uses compressed air to continuously transport concrete along the pipeline and spray it onto the construction surface. Concrete spraying machines are divided into dry shotcrete machines and wet shotcrete machines. The former is pneumatically conveyed dry-mixed material, mixed with pressure water at the nozzle, and then sprayed out; the latter is delivered by pneumatic or concrete pumps and the concrete mixture is sprayed out through the nozzle.
Preparation work before starting the shotcrete machine：
a、 Check whether the contacts of each circuit of the electric control system are firm and whether there is any leakage. Whether the grounding of the machine body is reliable.
b、 Observe the oil mark and check whether the lubricating oil in the reducer is sufficient
c、 Check whether the connection and fastening of each part of the concrete shotcrete machine are correct and reliable
d、 Run the shotcrete machine for a short time in order to grasp the rotation situation (pay attention to whether the direction of rotation is consistent with the direction of the arrow, but do not idling for a long time)
e、 Check the clamping force applied to the rubber sealing plate, first move the nut handle on the clamping device rod, and preliminarily tighten it. Then tighten 2-3 turns until there is no air leakage at the sealing plate.
Shotcrete machines are widely used in tunnels, culverts, subways, hydropower projects, and underground projects. This machine can be used for both wet spray and dry spray. There are two types of shotcrete machines: dry shotcrete machine and wet shotcrete machine.
The main features and advantages of the shotcrete machine:
Efficient and time-saving, the equipment is firm, durable, easy to maintain, and accessories are not easily damaged.
How to stop the shotcrete machine correctly:
After a day of work, the shotcrete machine will enter a "rest" state. Although it is about to end the operation, we should not relax, and we must draw a satisfactory end to today's work.