Benninghoven and Tarmac – an example of a longstanding and successful customer relationship

Overcoming changing market conditions together

It was more than 40 years ago that Tarmac first invested in Benninghoven technology: What started with a burner soon developed into an intensive collaboration between the British company for construction materials and solutions and the German specialist for asphalt mixing plants. The latest plant, a TBA 4000, is installed directly adjacent to a large construction site near Birmingham and produces asphalt for the expansion of a motorway.

Current reference: A-road project with a TBA 4000

Tarmac is the UK's leading business for sustainable construction materials, road contracting and construction materials, and has been successfully collaborating with Benninghoven for over 20 years. In these two decades, Tarmac and Benninghoven not only reacted to the changing market conditions, but also always took on a pioneering role. Specifically, this applied to reducing emissions, achieving a high recycling content and the must sustainable operation of the plants.

The latest joint project is an excellent example of this: Tarmac was awarded the contract for expanding the A47 Heartlands Parkway road in the Birmingham conurbation. To produce sufficient quantities of asphalt for this large project while keeping the transport distances short, the company invested in a new asphalt mixing plant of type TBA 4000.

“The quality of a partnership becomes particularly evident when it comes to customer service. The team of the Wirtgen Group in the UK is always ready with help and advice when we need support.”

Anthony Smith, Technical Director at Tarmac

Several Benninghoven plants supply asphalt for Tarmac

Tarmac is a leading supplier of construction materials, including aggregates, asphalt, cement, lime and concrete, and also supports its customers in the fields of road construction and recycling. The company currently has 7000 employees at 400 sites. The flexibility offered by Benninghoven is ideal for the range of different mixing plants operated by Tarmac. It is no coincidence that all these plants were supplied by Benninghoven. One of the reasons for this is that Benninghoven plants can reliably meet a range of different requirements for the asphaltic mixtures, but also for the sustainable operation of the mixing plants. These requirements are becoming increasingly stricter in many markets, including the UK, and consequently also affect Tarmac. In addition to this, the relationship between Tarmac and Benninghoven is based on mutual trust and cooperation. “The quality of a partnership becomes particularly evident when it comes to customer service. The team of the Wirtgen Group in the UK is always ready with help and advice when we need support,” says Anthony Smith, Technical Director at Tarmac.

“In addition to this, the Benninghoven plants support us in our efforts to achieve sustainable and efficient operation of the plants. They conserve energy, produce less and less emissions and allow us to add increasing amounts of recycling materials,” explains Miles Dobson, Head of Production at Tarmac.

“Our Benninghoven plants support us in our efforts to achieve sustainable and efficient operation of the plants. They conserve energy, produce less and less emissions and allow us to add increasing amounts of recycling materials.”

Miles Dobson, Head of Production at Tarmac

Transportable Benninghoven plant (TBA) at the Tarmac site in Washwood Heath.

Rubber granulate from car tires saves resources

The first job of Tarmac’s new TBA 4000 near Birmingham was quite a challenge: It was the first asphalt mixing plant in the British Midlands region to process rubber granulate from recycled car tires as an ingredient to keep the surface more elastic.

In addition to the virgin mineral and an asphalt component, the mixture for the A47 also contained this special aggregate. The new formulation protects resources, but also offers another advantage: It can be produced as a reduced-temperature asphalt or as a warm mixture. As the name implies, the temperature is lower compared to conventional mixtures. While the latter is usually mixed at 160 °C, reduced-temperature asphalt is produced at 100 °C to 110 °C. Compared to conventional hot mixtures, this saves fuel and CO₂ during the production process.

Reduced-temperature asphalt reduces CO₂ emissions

“The innovative asphalt contributes to sustainability,” explains Anthony Smith from Tarmac. “There is an eight to twelve percent reduction in CO₂. Contributions such as these are a central requirement for the British construction industry. We are encouraged to find new solutions that are more environmentally friendly. This has been a successful example.” A foam bitumen module from Benninghoven makes it possible to produce reduced-temperature asphalt: When hot bitumen is mixed with water, the bitumen foams up to many times its original volume, temporarily reducing the bitumen viscosity and therefore enabling the customer to produce and lay asphalt at lower temperatures – without affecting the asphalt properties.

The innovative reduced-temperature asphalt is a contribution towards more sustainability. We reduce CO₂ by eight to twelve percent. The mixing process is no problem at all for our TBA 4000.”

Anthony Smith, Technical Director at Tarmac

Improved environmental balance

The environmental balance is also significantly improved: With a daily output of 2,000 t of reduced-temperature asphalt, this adds up to savings of 1,800 l of heating oil (or another energy source) compared to hot mixtures, plus a 6 t reduction in CO₂ emissions. “The mixing process for our innovative formulation is no problem at all for our TBA 4000.” Road users can also benefit from this: Reduced-temperature asphalt cools down faster so roads can be reopened sooner.

Energy reduction with TBA plants in use at Tarmac

Learn more about reduced-temperature asphalt here.

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Independent from raw material prices

Combination burners offer independence from raw material prices: The efficient EVO JET burners from Benninghoven can be run with up to four different fuels. In this case, the fuel type for the plant can be changed from liquid gas to light oil at the press of a button.

Optimum control

For burning oil, the burner is equipped with a special nozzle in the combustion chamber which generates an ignitable fuel-air mixture. This allows for optimum dispersion of the oil particles, easy control of the flame and a wide regulation range of 1:8. This means that the burner can be regulated down to an eighth of the maximum possible power.

Recycling asphalt with Benninghoven plants

Cold feed is the preferred technology for asphalt recycling in the UK. Up to 30 % of reclaimed asphalt is incorporated into new mixtures. The moisture content is often around four percent or higher. This is where the Benninghoven cold feed system with multi-variable feed shows its strengths: It doses the material into the mixing process gradually and prevents water hammer events to protect the plant. This also guarantees high-quality asphaltic mixtures containing recycled materials.

The all-round talent: Benninghoven plants of type TBA

High-tech plant performance with a mixing output of up to 320 t
Plug & Work principle for fast installation, modular expansions and clear interfaces between Benninghoven and the customer for more sustainable plants
Recycling technologies
Users benefit from a high level of ergonomics and safety standards

Meeting market requirements with TBA technology

The TBA plant type stands for sophisticated asphalt mixing plants at a high quality level. In addition to this, the technology can be adapted to a variety of different market conditions. This was also true in the UK, as these examples show – going beyond Tarmac.

Market requirement: covered feed hoppers

Covered feed hoppers to keep the virgin mineral as dry as possible to ensure energy-efficient, low-emission and gentle production – not a problem with Benninghoven. The steel structures meet a variety of different customer requirements while helping to save energy: A 1 % moisture reduction in the mineral reduces consumption by 1 l of fuel for each ton of finished asphalt. For a daily production of 2.000 t, this equates to saving 2.000 l of oil or gas. This corresponds to the heating requirement of a detached house.

Market requirement: key transfer system

Key transfer system for more safety and increased productivity during maintenance work (for Benninghoven standard).

Market requirement: skimmer unit on the dust collection system

Skimmer unit instead of a precleaner on the dust collection system for more precise separation of the reclaimed filler and therefore a higher quality of the formulations.

Market requirement: multi-fuel burners

Burning several fuels at the same time. Depending on the model, EVO JET burners can be run with up to four different fuels – without any mechanical conversions. The change is executed at the press of a button.

Market requirement: precision weighing

Achieving optimum loading of the asphalt trucks through precision weighing (±50 kg) to fully utilize the maximum load while avoiding overloading. This is another contribution to reducing wear on the vehicles and to increasing safety.

Market requirement: blending bitumen

Options for blending bitumen to save tanks: Only a few basic bitumen types are stocked and then blended, i.e. mixed, in the bitumen weigh hopper in varying ratios, depending on the requirement.

Leading Benninghoven plant technology meets the highest requirements: A BA 5000 U at the Tarmac site in Harper Lane supplied the asphalt for resurfacing Silverstone Circuit.