The “green asphalt” devised by CETIM Technology Centre wins the 1st GAIN Innovative Materials Competition
The Emulcell project “Cold bituminous mixes additivated with nanocellulose” (biopaving alternative to conventional asphalt) led by the Ourense company Misturas, S.A. and in which the Roads, Geotechnics and Materials Group of the CITEEC of the UDC and the Advanced Materials Area of CETIM Technology Centre participated, has won in the Company & Research category of the 1st Innovative Materials Competition of Galicia. The event, promoted and organised by the Galician Innovation Agency (GAIN), coincided with World Materials Day.
The idea of this project, which offers a green alternative to conventional asphalt thanks to the incorporation of nanocellulose from wood waste, arose from CETIM’s previous knowledge of lignocellulosic materials and sustainable construction materials.
The synergies between the three entities have been key, and absolutely necessary, for the design and development of this innovative biopavement. Misturas, S.A. contracted the two research groups and the work was distributed in such a way that CETIM was in charge of designing and manufacturing new types of bituminous emulsions, in which different types of nanocellulose were included; for its part, Misturas S.A. and the UDC were in charge of designing and manufacturing new types of bituminous emulsions, in which different types of nanocellulose were included. and the UDC were in charge of integrating it into the bituminous mixes, searching for the optimum dosages, investigating its mechanical behaviour and testing the final result on a 50-metre-long test section built in Allariz (Ourense) to validate its performance on a real scale. Specifically, this biopavement is the result of the R&D&I project called Emulcell, developed between 2017 and 2020 with support from the Centro para el Desarrollo Tecnológico Industrial (CDTI).
An urgently needed green alternative
It is well known that bituminous mixtures or asphalt agglomerates have clear advantages for road surfaces, since, thanks to their slip resistance and ease of laying, they provide surface evenness and road safety. However, their manufacture has a high environmental impact, as they are made using petroleum derivatives and generate high pollutant emissions. In this context, the search for more sustainable formulas with the same technical performance was a top priority.
The alliance between CETIM Technology Centre, the University of A Coruña and the Ourense company Misturas, S.A. represents this green alternative, which has been distinguished by the experts of the GAIN Contest for its sustainability and for offering the market solutions with high added value, involving another key sector in Galicia, such as forestry. In addition, it was highlighted that the innovative mix achieves a pavement with better water resistance, a feature that is especially useful for roads located in rainy areas, as is the case in Galicia.
Extra and natural ingredient
The new material is a cold bituminous mix, suitable for forming part of the base of flexible road pavements – located under the surface wearing course. Specifically, it is a type of gravel-emulsion in which the asphalt agglomerate has been added with nanocellulose, improving some of its performance compared to conventional mixes.
The material has a better environmental performance since the bituminous emulsion replaces part of the bitumen content (derived from petroleum) and the additives necessary for its stabilisation with a product of natural origin. It also opens the door to obtaining more sustainable and less polluting pavements, favouring the circular economy in construction.
The collaboration between the three entities has been so satisfactory that, while they continue with the industrial development of this “green asphalt”, they are preparing a new R&D project to be launched in 2022.