5 Infographs of innovation projects that contribute to sustainable development

1. Mycorrhizas to stabilize embankments being built

Embankments are part of road building projects with variable slopes that continuously present problems of erosion. Very little vegetation grows on steep embankments, so other methods such as wire mesh need to be used to avoid erosion and the loss of material from the embankment.

ACCIONA has developed a more sustainable alternative: erosion control on embankments using mycorrhizas. Mycorrhizas are fungi, natural organisms in the soil that create symbiotic links with plants. The fungus feeds the plant with they mineral nutrients and water they need to grow, making its roots bigger. As they expand, the plant returns carbohydrates and vitamins to the fungus that it is not capable of generating itself. This helps the growth of plants on embankments in adverse temperature and humidity conditions when there is a lack of nutrients. It also extends the plant’s roots, thus avoiding erosion of the soil. This solution re-establishes the natural ecological balance of the soil and improves the general appearance of the embankment by helping it to blend into its surroundings. It is an environmentally sustainable solution that is also efficient.

The solution has been applied in several civil works projects in Spain, for example:

• AVE High-Speed Train: Villaverde de Medina-Villafranca de Duero (Valladolid). April 2011.
• AVE High-Speed Train: Atlantic axis: Vilagarcía de Arousa-Catoira (Pontevedra) section. November 2011.
• AVE High-Speed Train: Riudellots-Joan Torró (Girona). December 2011.
• AVE High-Speed Train: Rail hub of La Encina (Alicante). April 2011.
• AVE High-Speed Train: Atlantic axis: Vilagarcía de Arousa-Catoira (Pontevedra) section. October 2012.
• AVE High-Speed Train: León-Asturias. Sotiello-Campomanes section: October 2012.
• A2 expressway: Torija, Guadalajara. November 2014.

 2. Bioremediation for soil contaminated with hydrocarbons

This project arose from the need to clean soil contaminated by hydrocarbons so that it could be used for different projects. This kind of soil cannot be used unless they it is decontaminated or sent to a landfill. The difficulty involved in carrying soil to a landfill is the impact on earthworks. Its transport is not only complex and tedious, it is also highly polluting, and so are the classic decontamination treatments that use chemical compounds and have a big impact on the environment.

ACCIONA has developed a sustainable alternative treatment: bioremediation. This process eliminates pollutants by using microorganisms that come from the soil itself. Bioremediation reduces the environmental cost of conventional treatments and also eliminates up to 80% of hydrocarbons in just one month, which means it is an efficient and sustainable solution.

This solution is currently being tested in a pilot plant in ACCIONA Infraestructuras’ machinery pool in Noblejas.

3. APSE Project: Sustainable road construction and maintenance

Road building is a process that has a high impact on the environment. The materials most commonly used are oil-based products or stone extracted from quarries. Therefore, the level of energy consumption and contaminating emissions is high.

The ASPE project emerged from the need for a new, sustainable design of asphalt pavement. This pavement has similar properties to conventional ones, but it is built using recycled materials that generate a lower environmental impact. Through a combination of materials that are environmentally more efficient, such as rubble from demolition and construction, recycled pavement, ligands of plant origin or bio-polymers from a waste product from the production of bioethanol. This significantly reduces the carbon footprint associated with the construction and maintenance of roads.

In the near future this project will be applied to some of the roads in the region of Madrid to evaluate its effectiveness.

4. A polymer product to eliminate dust from roads that have not been asphalted

One of the most common problems associated with unpaved roads is the amount of dust generated as vehicles pass by. Dust is a risk factor for drivers, as it hinders visibility. To reduce the level of dust, the roads are usually hosed down every day. This obviously means the use of enormous amounts of water, so it is not an environmentally acceptable practice.

ACCIONA has developed a sustainable alternative solution to eliminate dust from unpaved roads, a polymer-based product that eliminates dust in suspension with a single spraying. It improves drivers’ visibility and helps to stabilize the soil. It is a more sustainable solution because it saves enormous amounts of water and respects the environment. It also reduces costs, which makes it economically viable.

ACCIONA has carried out 15 experiences internationally, and 2 at national level in Chile and Canada, of the application of this product. They have all been successful.

5. A photocatalytic additive to improve pollution levels in cities

Pollution in cities is a serious problem that affects the environment and people’s health. ACCIONA has developed a product which, applied to pavements and buildings in contact with solar radiation, creates a series of chemical reactions that eliminate certain pollutants such as volatile organic compounds (VOC) or nitrogen oxide (NOx). The product converts these molecules into innocuous (harmless) compounds. The use of this product leads to a big reduction in pollution in cities, and it also improves the appearance of buildings by preventing the accumulation of dirt on their surfaces.

The solution has been applied to a number of projects, for example:

• Streets in Madrid: Avenida de Betanzos and Lope de Haro.
• The new bus station in Ávila, on concrete pavement.
• Urban Planning Program in La Rosilla.
• Lecture hall building in the Universidad Carlos III, on prefabricated concrete slats.
• The ACCIONA Valportillo building, on the cobblestone paving in the car park.