Main Spare Parts of Shotcrete Machine

Shotcrete Machine Spare Parts

Main spare parts: hopper, rotor, sealing plate, rotor lining plate, rubber spring, delivery rubber hose, mixture chamber, taper sleeve, rubber elbow, spray nozzle, clamping device, joint plate, quick couplings etc.

1. Rotor lining plate:

Features: smooth surface, high hardness, high wear resistance, high pressure resistance.

Structure features: there are two rotor sealing plate besides the rotor body. The inner hole are air hole while the eight outer holes are material unloading holes.

Material: high manganese steel, or stainless steel.

Applications: In rotor-type shotcrete machine, the rotor lining plates work with sealing plates as a sealing part besides the rotor. It is the main component of shotcrete machine, and should be checked and replaced regularly.

2. Rubber sealing plate:

Features: high flexibility, high wear resistance, anti-aging, high pressure resistance, impact resistance.

Structure features: there are a upper sealing plate and a lower sealing plate close to the two rotor lining plates. The inner hole are air holes while the fan-shaped hole of upper sealing plate and the outer hole of the lower sealing plate are material unloading hole.

Material: Polyurethane

Applications: In rotor-type shotcrete machine, the sealing plates work with rotor lining plates as a sealing part. It is the main component of shotcrete machine, and should be checked and replaced regularly.

3. Spraying hose (Delivery rubber hose )

Features: high wear resistance, high toughness, high pressure resistance.

Material:

 Internal layer: the main raw material are polyurethane and butyl rubber, added with special reinforcing agent.

 Reinforcing layer: 

fabric reinforced spraying hose adopts high-quality rubber fabric as reinforcing layer, which has good flexibility and pressure resistance.

steel braided spraying hose adopts steel wire woven layer with excellent pressure resistance and flex resistance, which can endure 3-4 times of the working pressure.

Specification:

 Hose inner diameter: 51mm, 57mm, 64mm

 Hose length: 14m, 20m

4. Taper sleeve, rubber chamber, rubber elbow

Features: high wear resistance, high abrasion resistance, high pressure resistance, high impact resistance.

rubber chamber

rubber elbow

Taper sleeve

spraying nozzle

Ref:

KEMING KPZ Dry Shotcrete Machine
Dry Shotcrete Machine Spare Parts
Main Products: shotcrete machine / gunite machine, concrete pump, grouting pump, plaster machine, concrete mixing machine, concrete foaming machine, etc.

Overview of Dry Shotcrete Machine

Overview of Dry Shotcrete Machine

 (eg. KPZ-5 Dry Shotcrete Machine )

1. Dry Shotcrete Machine

Dry Shotcrete machine (Gunite machine) is a dry concrete spraying device. In dry concrete spraying operation, the cement& sand mixture is sprayed at a high velocity and pressure, and then mixed with water by the operator at the nozzle end. Due to its advanced spraying technology, it gets wide use in all kinds of concrete projects.

2. Machine structure

Take KPZ-5 rotary type shotcrete machine as a example.

Generally, a shotcrete machine includes the mixing hopper, rotor assembly, air system, travelling system, spraying system, driving device (electric motor/ diesel engine/ pneumatic motor).

3. Working principle

Generally, the concrete is fed into the gunite machine hopper, driven by high-pressure air to the nozzle, mixed with water at nozzle, and then sprayed to the working surface.

Concrete mixture (cement, sand, gravel etc.) is unloaded from a concrete mixer outlet (or manual mixing and feeding), and drops through the vibrating screen to the mixing hopper (#1). Then, mixture will be mixed by the agitator (#2) to all-through plastic chamber (#6), and transferred to discharging outlet along with the rotation of rotor (#5), where compressed air from air chamber (#13) blows the mixture to outlet elbow (#9). Another blow of compressed air from the rotational swirler will further accelerate and rotate the mixture to the conveying pipe. Finally, the concrete mixture will be sprayed out through the nozzle where a little water is added.

4.Application:

1. Dry Shotcrete Machine can spray plain concrete and fiber concrete in engineering construction, such as tunnel, culvert, subway, hydroelectric works, underground works and mining laneway etc.

2. spray fiber materials , such as refractory and thermal insulation materials etc.

3. soil spray-sowing ( soil, seed, fiber, soil amendment, pesticides etc.) in ecological environment construction.

Ref.:

1. Website: Henan Coal Scientific Research Institute Co., Ltd.

2. Google Plus: Henan Coal Scientific Research Institute

3. Main Products: shotcrete machine / gunite machine, concrete pump, grouting pump, plaster machine, concrete mixing machine, concrete foaming machine, etc.

Differences Between Gunite and Shotcrete

Differences Between Gunite and  Shotcrete

Generally, when concrete is sprayed at a high pressure, it is called shotcrete, due to the fact that it is 'shot' on the surface. There are actually two types of shotcrete―wet mix and dry mix shotcrete. It is this dry mix shotcrete that is commonly called gunite, just because the applicator is gun-shaped. The other type, wet mix, is simply called shotcrete. 

Let's dive right into the gunite and shotcrete comparison.

Items	Gunite	Shotcrete
Basic difference	The cement& sand mixture is sprayed at a high velocity and pressure, and then mixed with water by the operator at the nozzle end.	Concrete mixture of cement and water is ready-made previously, and then sprayed at a high velocity and pressure.
Equipment	Gunite equipment is made up of a dry mixture container, a large air compressor, a hose, and spray nozzle. The air compressor is much larger than that for shotcrete, since more air pressure is required for spraying gunite than for shotcrete. The spray nozzle is connected to a pressurized water source. The water-cement ratio (W:C) has to be controlled by the operator. The hose of the equipment is much lighter, since it contains mostly air, carrying a mixture of sand and cement. In general, this equipment is more complicated than that in case of shotcrete.	Shotcrete equipment consists of a hopper containing the wet mixture, an air compressor, a hose, and a nozzle. The air compressor is much smaller. The spray nozzle is not connected to a separate water source, since the mixture already contains water. The operator can control the rate of concrete spray. The hose is slightly heavier than that in the gunite process, since it contains the much heavier water-cement-gravel mixture. Shotcrete equipment is much simpler, and requires less individuals to operate it.
Material	This is a mixture of fine-grained cement and sand. Water is mixed only at the nozzle.	This is a mixture of cement, sand, and aggregate such as pea gravel with water. The mixture has large-grained particles.
Application process	1.Pressurized air from the compressor enters the container and carries the cement dry mixture through the hose. 2.As the mixture exits the hose, the operator mixes the cement with water at the nozzle. 3.The complete mixing of the cement and water only occurs on impact with the surface.	1.Pressurized air from the compressor drives the water-cement mixture out into the hose. 2.The mixture exits the nozzle at a high velocity. The operator has to continuously vary the rate of spray to ensure a consistent concrete layer formation.
Advantages	1.The material for gunite being dryer, becomes harder on curing. 2.Higher compressive strength than shotcrete (7,000 to 9,500 psi). 3.The cement mixture being mixed on-site, provides more work time. 4.Smoother surface finish. 5.No shrinkage cracks formed. 6.In terms of cost, this process is comparatively cheaper.	1.In shotcrete, a skilled worker is required, but not as technically trained as a gunite operator, since shotcrete errors are less critical. 2.Less rebound materials formed, which can be compacted over the floor towards the end. 3.Because shotcrete is a premixed mixture, it forms a strong and consistent coating. 4.Less time requirement.
Disadvantages	1.Requirement of a highly skilled operator. 2.More room for error due to manual control of the water-cement ratio. 3.Generation of more rebound material, requiring excessive cleanup, leading to time loss. 4.Use of rebound material in pool construction may lead to weak spots, causing cracking and waterproofing loss. 5.Gunite application results in a lot of dust generation, the level of which depends on the skill of the operator. 6.Gunite application may cause inconsistent coating, leading to formation of weak spots. 7.Gunite being a dry, stoneless mixture, may clog the hose pipe. 8.Limited structural applications due to finer grade of cement. 9.Requirement of special paints for gunite finishing.	1.Lower compressive strength than gunite (6,500 to 7,500 psi). 2.When shotcrete mix is prepared in the factory, it has to be applied within a short span of time (generally within 90 minutes). 3.To prevent cement from hardening in the hopper, the operator may have to add more water to the cement mixture, which greatly compromises the rigidity of the final product. 4.Formation of shrinkage cracks. 5.In terms of cost, this process is comparatively expensive.

Ref.:

1. Website: Henan Coal Scientific Research Institute Co., Ltd.

2. Google Plus: Henan Coal Scientific Research Institute

3. Main Products: shotcrete machine / gunite machine, concrete pump, grouting pump, plaster machine, concrete mixing machine, concrete foaming machine, etc.

Shotcrete/Sprayed Concrete Market In 2016

Shotcrete/Sprayed Concrete Market 2016

Shotcrete is a method of applying concrete that is generally self-supporting without the need for form work. Shotcrete is conveyed through a hose and pneumatically projected at high velocity onto a surface, as a construction technique. The key applications of shotcrete are tunnel linings, mining operations, rehabilitation works, refractory systems, and others. The demand for shotcrete is influenced by its versatile and innovative characteristics as it can be projected onto any shape of surface along with vertical and overhead areas.

Europe – The biggest market for shotcrete/sprayed concrete

Shotcrete/sprayed concrete is projected to be the leading market in Europe mainly due to the presence of emerging markets. Also, the developing tunneling and mining activities in the underground construction and civil construction industries in Europe are the reasons for the growth of the shotcrete market in this region. Europe is the largest market for shotcrete with a share of more than 37% of the global market in terms of volume in 2014. Europe is projected to invest huge amount in tunneling, mining projects, due to the increasing demand for low-cost housing, need for underground transportation, and availability of raw materials for shotcrete technology. Increasing demand for wet-mix process has been observed in Europe owing to continuous industrialization and growth of the underground construction sector.  

Wet-Mix Process – The fastest-growing process segment of shotcrete/sprayed concrete

In the wet-mix process, all ingredients, such as, cement, concrete, aggregates, and other admixtures including water, are thoroughly mixed and introduced in the delivery equipment. Wet material is pumped to the nozzle where compressed air is added to provide high velocity for placement and consolidation of the material onto the receiving surface. The wet-mix process is the fastest-growing process segment of shotcrete market. Europe is currently the largest user of wet-mix shotcrete process. This process segment accounted for a share of around 80% of the total shotcrete market in terms of volume in 2014. Wet-mix process is always used when high set concrete quality is specified and high output is required. This process is by far the most popular in mechanical tunneling. Wet spraying is the more modern and efficient method of installing shotcrete. It is a suitable process for various application industries, such as underground construction, tunneling, and mining industries.

Underground construction – The largest market for shotcrete/sprayed concrete

The underground construction is the largest application industry for shotcrete and this trend is projected to continue in the near future due to the increasing infrastructural developments, growing need for transportation, and underground excavations. Shotcrete was the largest application in Europe, for the underground construction industry in 2014 due to the accelerating tunneling and mining activities. This application segment accounted for a share of around 60% in terms of volume of the total shotcrete market in 2014. Water retaining structures is projected to be the fastest-growing application segment, followed by repair works and protective coatings, between 2015 and 2020, due to the increasing demand of civil construction in developing countries, such as India, Nigeria, and Philippines.

The shotcrete market is also segmented on the basis of system of spraying namely, robotic spraying system and manual spraying system. Robotic system accounts for the largest share of the market as it is mainly used to spray wet mix shotcrete, which is very heavy in weight and cannot be sprayed manually.

Henan Coal Scientific Research Institute Co., Ltd. is a professional Shotcrete/Sprayed Concrete Machine manufacturer with 36-year experience, mainly producing shotcrete/sprayed concrete machine / gunite machine, concrete pump, grouting pump, plaster machine, concrete mixing machine,concrete foaming machine, etc.

NOTE: Segments of the report “Shotcrete/Sprayed Concrete Market by Process (Wet - Mix & Dry - Mix), by Application (Underground Construction, Water Retaining Structures, Protective Coatings, Repair Works & Others), by System (Robotic & Manual) and by Region - Global Trends and Forecasts to 2020’’

Ref.:

1. Website: Henan Coal Scientific Research Institute Co., Ltd.

2. Google Plus: Henan Coal Scientific Research Institute