Portuguese 
Spanish 
Pilot project applies asphalt with olive pits in 2,000 square meters of Barcelona, uses biochar from agricultural and forestry waste, replaces mineral aggregate, and records an initial 76% reduction in carbon footprint, while tests evaluate durability, thermal stability, moisture resistance, cracks, and traffic throughout the year.
The asphalt with olive pits is being tested on a stretch of approximately 2,000 square meters in the Eixample neighborhood, in Barcelona, Spain, in 2026. Developed by construction companies and university researchers, the mixture replaces limestone aggregate with biochar produced from carbon-rich agricultural and forestry waste.
According to The Daily Galaxy, on July 13, 2026, initial data indicates a 76% reduction in carbon footprint compared to traditional mixtures. The project now needs to demonstrate, on a real street, how the pavement reacts to traffic, summer heat, and moisture in the colder months.
Street looks common but hides another composition
Those who pass by the experimental stretch find a black surface, compacted and leveled with the curb, visually similar to any other urban road. The difference lies in the composition used below the apparent layer.
-
New study suggests that just 24 hours in space can accelerate liver aging and cause genetic changes; the research used data from NASA astronauts.
-
The water that disappears between the tectonic plates can embark on an almost unbelievable journey through the Earth’s interior, reach the boundary of the metallic core, and trigger a chemical reaction that has been silently transforming the heart of the planet for billions of years.
-
Big Boy 4014: the largest operating steam locomotive in the world weighs 544 tons and crosses the United States
-
A 9-year-old autistic boy took $100 from his own piggy bank, assembled 5 emergency kits to help other children during rescues, and mobilized the community to distribute 61 backpacks with noise-canceling headphones, sensory toys, and communication cards to police, firefighters, hospitals, and schools in the United States.
Instead of the limestone aggregate normally used in paving, the mixture incorporates biochar obtained from olive pits and pine residues. The goal is to reduce the consumption of mineral raw materials and keep part of the plant carbon stored within the pavement.
Project brings together construction companies and university
The proposal was developed by the companies AgustĆ i Masoliver, known as AMSA, and Asfaltos y Construcciones Elsan, ELSAN. Researchers from the Polytechnic University of Catalonia are participating in the technical validation of the mixture.
The initiative also received institutional support from Barcelona. The collaboration between companies, the university, and municipal administration allowed the material to move beyond the laboratory environment and be applied to a road subjected to daily use.
Biochar replaces limestone in the mixture
Traditional asphalt uses mineral aggregates to form a structure resistant to the weight of vehicles, temperature changes, and the presence of water. In the Catalan project, a central part of this function is taken over by a material produced from organic waste.
The asphalt with olive pits incorporates biochar, a solid and carbon-rich substance. In addition to utilizing by-products of the olive oil industry, the solution seeks to reduce the extraction and transportation of limestone normally used in roadworks.
Pyrolysis prevents carbon from quickly returning to the air
To transform the pits into biochar, the material undergoes pyrolysis. In this process, organic matter is heated in an environment with little or no oxygen, avoiding conventional combustion.
Without enough oxygen to burn completely, the carbon remains in a solid and stable structure. Instead of being quickly released as carbon dioxide, it can remain trapped in the biochar for decades, as long as the pavement remains preserved.
Olive trees remove carbon dioxide from the atmosphere
During growth, olive trees absorb carbon dioxide from the air and incorporate part of this carbon into plant tissues, including the pits. When these residues decay or are burned, the carbon tends to return to the atmosphere.
Pyrolysis alters this cycle by stabilizing the plant matter. When the biochar is inserted into the asphalt, the street functions as a form of carbon storage during the pavement’s lifespan.
Initial reduction reaches 76%
The first data presented by the project indicate a 76% reduction in the carbon footprint compared to traditional paving mixtures. The calculation considers both the replacement of the mineral aggregate and the carbon retained in the biochar.
The result, however, still depends on the performance of the section over time. A significant reduction in emissions will only provide practical advantage if the new material maintains sufficient durability to avoid frequent repairs and replacements.
Laboratory tests indicate resistance
Before being applied on the street, the mixture was subjected to laboratory tests. The results indicated performance at least equivalent to conventional asphalt in criteria considered essential for urban infrastructure.
The analyses evaluated moisture resistance, tolerance to crack formation, and stability in the face of temperature changes. In some of these criteria, the formulation with biochar showed superior results compared to the traditional mixture.
Real traffic will be the decisive test
The experimental section needs to show how the material behaves under vehicles, braking, acceleration, and continuous load passage. Real conditions are more varied than those reproduced in the laboratory.
Engineers will also monitor the wear caused by the seasons. The test should reveal if the asphalt with olive pits withstands the heat of Barcelona’s summer, humid periods, and thermal changes without deforming or developing premature cracks.
Annual cycle will help define new contracts
The intention is to observe the pavement for at least one full cycle of climate and traffic. This period will allow comparing laboratory predictions with the behavior effectively recorded on the street.
If the surface maintains stability, the data can be converted into technical specifications. This information is necessary for municipal engineers to include the material in future contracts for street and sidewalk reconstruction.
Contest aimed to reduce emissions from works
The project was selected in an urban challenge aimed at the so-called 21st-century road section. The initiative was organized by the BIT Habitat foundation, linked to the Barcelona City Council, with participation from BIMSA and the provincial administration.
The proposals needed to reduce carbon emissions, water consumption, and the use of raw materials without compromising durability. The central requirement was to demonstrate that sustainability and structural performance could advance together.
Teams received funding for prototypes
The winning projects received funding of 90,000 euros for the improvement and development of the prototypes. The work was scheduled to continue until September 2026.
Public support reduced a common barrier faced by experimental materials. Many solutions remain confined to laboratories because they do not find funding, urban space, or contracts capable of supporting real-scale tests.
Barcelona aims for climate neutrality
Barcelona’s Climate Plan sets the goal of achieving climate neutrality by 2030. In this effort, streets and sidewalks have come to be considered significant sources of emissions associated with public works.
Paving consumes raw materials, energy, and transportation, and requires maintenance over time. By testing a lower-impact alternative, the city seeks to include road infrastructure in a climate strategy that previously focused mainly on buildings, energy, and mobility.
Spain has raw material on a large scale
The choice of olive pits is also related to regional availability. Spain is the world’s largest producer of olive oil and generates large volumes of this waste during each processing period.
This existing chain can provide raw material without requiring new agricultural areas. Instead of planting specifically to produce biochar, the project takes advantage of a byproduct that would already be discarded, burned, or destined for other forms of processing.
Pine waste completes the formulation
The mixture applied in Barcelona does not use only pits. Pine waste, common in Mediterranean production chains, is also transformed into biochar.
The combination broadens the supply possibilities and reduces the dependence on a single residue. The model can be adapted according to the local availability of agricultural and forestry materials, provided that the technical characteristics are duly tested.
Supply chain is also being evaluated
The technical success of the pavement is not enough to ensure its adoption. The project needs to verify if there is a regular quantity of pits, industrial capacity to perform pyrolysis, and logistics to transport the biochar to the asphalt plants.
Scaling up may also alter costs and operational requirements. The urban test serves to evaluate both the street’s resistance and the possibility of transforming dispersed residues into a standardized input for public works.
Concrete could be another destination for biochar
Related research also evaluates olive pit biochar as a component of concrete mixtures. In this case, the material was studied as a partial substitute for natural sand.
The results mentioned by the source indicate a reduction in the carbon footprint and improvement in water penetration resistance. The application in concrete could significantly expand the use of biochar, as this material is present in buildings, bridges, roads, and various infrastructure works.
Application does not eliminate the need for caution
Although the initial results are promising, there is still no proof of performance over many years of use. The pavement needs to withstand different climatic conditions and levels of wear before being considered a consolidated alternative.
It will also be necessary to assess maintenance, costs, residue availability, and recycling possibilities. The project does not declare the immediate end of traditional asphalt but presents a concrete route to reduce emissions without abandoning urban resistance requirements.
Streets can become carbon reservoirs
The olive pit asphalt transforms an agricultural waste into part of an infrastructure used daily. If the technology is validated, streets and sidewalks could store carbon throughout the material’s lifespan.
The benefit can grow when added to thousands of municipal projects. A single road represents a test, but adoption in different neighborhoods could turn urban paving into a complementary tool for decarbonization policies.
Result will determine if the experiment can advance
The continuation of the project will depend on data collected from the CerdĆ street section and its test area in Eixample. Engineers will observe wear, cracks, stability, and reaction to water before recommending further applications.
If the performance is confirmed, Barcelona could incorporate the mix into common public procurement processes. Do you believe that olive pit asphalt can replace part of conventional pavements, or do durability risks still require more caution? Leave your opinion in the comments.
