Total EcoSolutions: Why we have introduced warm-mix bitumen products
Traditionally, asphalt is manufactured at elevated temperatures of between 150 and 200°C, but this inevitably creates challenges relating to energy consumption, high fume levels and risk of contact burns.
For these reasons, Total Bitumen’s strategy is to reduce working temperatures while maintaining end-product performance. Azalt® ECO² and Styrelf® ECO² are the result of this work, but what benefits do these products bring over standard bitumen in hot-mix asphalt?
The environmental benefits
One of the most important benefits of warm-mix products is that they use less energy when they are being mixed and laid, reducing costs. Since Total’s ECO² products enable up to a 40°C reduction in mixing and compaction temperatures, asphalt manufacture requires significantly less energy. As a result, energy consumption at the point of mixing can be reduced by up to 35%.
Lower energy use also makes warm-mix bitumen less carbon-intensive. Globally, industry accounts for around 21% of greenhouse gas emissions (GHGs). While this comprises a wide range of activities, every industrial business must do what they can to reduce GHGs to avoid climate change, and what’s more, if innovations such as carbon credits are introduced, reducing emissions will give businesses a clear reduction in costs. To help customers meet their targets, Total’s ECO² technology can reduce GHG emissions by up to 30% at the point of mixing.
ECO² products benefit the local environment too, reducing emissions at the point of laying by up to 50%. This makes asphalt installation less disruptive to the public as odour and steam are reduced significantly.
Improved health and safety
For workers laying asphalt, warm-mix provides a range of benefits. Firstly, the reduced heat and fumes associated with lower temperatures ensure that working conditions for site personnel are far more comfortable.
Roller-generated steam is reduced due to the lowered temperature of the asphalt mat, thereby improving visibility for workers and the travelling public. This is important as workforces often only have limited safe working zones between themselves and live traffic, making good visibility critical.
Enhanced technical performance
A significant benefit of ECO² warm mix asphalt is the fact that, despite the reduced working temperatures, the performance of the finished asphalt is at least equivalent to equivalent hot-mix asphalts.
Cooling rates are also improved. Asphalt must reach a safe trafficking temperature to avoid initial rutting. This technology can reduce cooling time by over 50% improving productivity, reducing contract times and reducing costs.
Asphalt produced with Total’s ECO² binder is easily compacted. Enhanced compaction can offer savings by replacing multiple layer construction with single lift thicker layers. This innovation saves valuable contract time by removing interfacial joints - a potential weakness in road construction.
Increased workability means asphalt manufacturers can potentially deliver product further afield. When conventional asphalt is transported over long distances the logistical range is often restricted by temperature loss in the asphalt. ECO² offers potentially longer haulage times to transport the product further without compromising workability.
For clients wishing to make their roads more environmentally sustainable, warm-mix can also incorporate recycled asphalt planings (RAP).
Lowering mix temperature prevents further oxidation of the binder within the RAP reducing premature ageing during manufacturing, loading, transportation and laying of the asphalt.
Total’s ECO² solutions improve the environment, compared to hot-mix bitumen, enabling enhanced productivity, durability and safety. For more information on Total’s range of ECO² binders and to find out how they can benefit your project, please contact our experts.