We can all agree that constructing tunnels requires more than just a concrete mixer – the degree of mechanisation is relatively high. If you are interested in the type of construction materials needed for tunnel construction, keep reading this brief introductory guide. Moreover, if you require reliable concrete mixers to get started on your next construction project, BS Power is here to help!

 

BS Power is touted for our wide range of some of the best high-performance construction equipment. If you would like to know more about our construction products, browse our catalogue and pick out the perfect tools to get the job done.

 

Tunnel Construction: Concrete Mixers And More

 

While it would take quite a few articles to go about underpinning tunnel construction in its entirety, the following equipment plays pivotal roles in the construction process:

 

• Concrete pumps
• Concrete mixers
• Concrete mixing plant
• Generator sets
• High-lift pumps
• Large electric air compressors
• Dump trucks
• Side-turn loaders
• High-power ventilators
• Constant-pressure water supply equipment
• Concrete jets
• Grouting machines
• Rock drills
• Crushed stone processing equipment
• Excavators
• Special formwork for self-processing
• Large-capacity transformers, and more

 

 

• Concrete Mixer Station: Responsible for blending concrete for tunnel construction and dry sprayed concrete.
• Concrete Mixer Truck: Used for transporting mixed concrete to the construction site.
• Concrete Mixer Pump: Facilitates concrete pumping into the concrete truck, followed by pouring it on-site.
• Generator Set: Acts as a backup power source for tunnel power supply in case of grid power failure.
• Large Transformer: Assists in providing electricity for tunnel construction.
• High-Lift Pump: Conveys water from the lowest point to a reservoir located about 50 metres above the tunnel, supplying high-pressure water essential for tunnel construction.
• Constant Supply of Pressure Water Equipment: Provides rated pressure water to areas lacking a high-level pool, feeding the high-pressure pipe network.
• Large Air Compressor: Supplies high-pressure air to the tunnel construction face, with typical wind pressures reaching 5-7 kg/cm2.
• Rock Drill: Essential for drilling blast holes, also known as a pneumatic drill.
• High-Power Ventilator: Crucial for tunnel ventilation to maintain optimal air quality.
• Dump Truck: Typically 12 to 15 tons, employed for transporting materials from the caverns.
• Rollover Loader: Specialised equipment for loading caverns onto dump trucks.
• Excavator: Aids in removing loose ballasts from the working face and assists with tunnel invert excavation.
• Grouting Machine: Utilised for grouting into the ground or bolting holes.
• Rebar Processing Equipment: Helps process rebar for construction purposes.
• Tunnel Formwork Trolley: A comprehensive formwork system for tunnel lining, equipped with hydraulic cylinders for both vertical and horizontal movement.
• Crushed Stone Processing Equipment: This equipment compacts cave balls into crushed stone, to be used as concrete material.

 

Know Your Concrete Mixers

 

A concrete or cement mixer combines gravel, sand, cement, water, and admixtures to produce concrete, either as a standalone unit or in tandem with other devices.

 

 

Concrete mixers are categorised based on mixing principles, mobility, and work nature:

 

• Drum Mixer: Also known as a self-falling concrete mixer, it efficiently mixes materials using gravity, making it ideal for small to medium-sized projects.
• Twin Shaft Mixer: This mandatory mixer features dual horizontal mixing shafts for uniform and high-quality mixing, adaptable for various applications.
• Planetary Mixer: Offering efficient, complex mixing patterns, this mixer is suitable for a wide range of applications due to its low noise, low pollution, and compact design.
• Self-Loading Mixer: Combining mixing, loading, transportation, and unloading functions, it excels in projects with limited space, offering time-saving, efficient operation with minimal manpower.

 

Selecting the right mixer is paramount in tunnel construction, ensuring efficient progress aligned with project requirements. Key considerations include the type of mixer, output capacity, configuration options, and manufacturer’s capabilities and support.

 

Selecting The Correct Concrete Mixer

 

Selecting the appropriate mixer is a pivotal aspect of tunnel construction. Ensuring that materials align with project specifications is key to achieving efficiency and project success. Key considerations include:

 

• Concrete mixer types
• Output capacity
• Configuration options
• Manufacturer expertise and support

 

Drum Concrete Mixers

 

Often referred to as the self-falling concrete mixer, the drum mixer employs a unique process. During stirring, it raises materials to a higher position, after which gravity takes over, causing them to descend. As the drum rotates, the dropped materials undergo thorough and uniform mixing. The drum rotates forward for mixing and reverses to discharge the blend.

 

Noteworthy for its cost-effectiveness and low maintenance, this drum concrete mixer shines in small to medium-sized projects.

 

Drum mixers come in two main varieties based on power sources: diesel and electrical. Diesel concrete mixers, particularly favoured by customers, operate independently of external power sources, directly powered by diesel engines. They are available in two models with discharge capacities of 500 and 350 litres, offering flexibility to suit diverse needs.

 

The concrete mixer drum is often utilised independently for concrete production, allowing customers to select the most suitable type and model based on their specific requirements.

 

Twin Shaft Concrete Mixers

 

The twin-shaft mixer, a mandatory mixing machine, features two horizontal mixing shafts within the mixing cylinder. Stirring blades, driven by these shafts, continually mix the materials, resulting in a uniform and high-quality mixture. This mixer boasts wide applicability, high mixing efficiency, low failure rates, and extended service life.

 

The twin-shaft mixer can operate autonomously or in conjunction with other equipment. It can be combined with components like cement silos, screw conveyors, and aggregate batching machines to form a concrete mixing plant for mass commercial concrete production.

 

Similarly, it can be integrated into a brick machine production line for high-quality brick manufacturing. When selecting a twin-shaft mixer, consider its intended use, configuration options, and output capacity to ensure a suitable choice.

 

Planetary Concrete Mixers

 

The planetary concrete mixer often likened to the vertical shaft mixer due to its appearance resembling a planet, is another essential in the mixer family. Its mixing blade and mixing arm execute compound rotations and revolutions, creating a complex mixing trajectory that ensures efficient and uniform blending.

 

Widely used in various industries, including prefabricated components, concrete walls, refractory materials, glass, ceramics, and concrete bridge frames, this mixer is celebrated for its low noise, pollution-free operation, compact structure, excellent mixing performance, secure sealing, and energy efficiency.

 

It boasts global popularity and, much like twin-shaft mixers, can work independently or be integrated into a production line for superior concrete production.

 

 

Self-Loading Concrete Mixers

 

A newcomer in the realm of mixers, the self-loading concrete mixer is a versatile machine with four core functions: mixing, loading, transportation, and unloading, akin to a small mixing plant. It can be categorised into two types: self-loading pan mixers and self-loading drum mixers. The key distinction lies in the type of mixer used.

 

Self-loading mixers find their niche in various infrastructure projects such as foundation laying, road construction, ditch creation, and tunnel development. Their advantages include compact dimensions, a small turning radius, and a short wheelbase—making them ideal for projects with limited space.

 

These mixers feature a mixing tank capable of rotating 270 degrees, allowing unloading from all sides without repositioning, saving time and enhancing efficiency. With user-friendly operation, a single person can manage the entire machine, reducing manpower requirements to just 3 to 5 individuals.