What is the environmental impact of the asphalt roads we walk and drive on every day? While asphalt is known for its durability and strength, asphalt pavements frequently present with cracks, potholes, rutting, and upheaval. The frequent need for repairs makes it a relatively unsustainable solution, which is why it’s important to consider its environmental impact.
Learn about the impact asphalt has on the environment and some environmentally friendly asphalt alternatives.
One of the most widespread production materials, asphalt comes from a combination of an aggregate and a binder. The aggregate usually includes sand, gravel, or crushed stones, while bitumen is a sticky black substance that binds it together. When the substances are mixed at high temperatures, they combine to form asphalt.
Making asphalt requires specific conditions to be met, including:
Asphalt does not need to cure and can withstand foot and car traffic as soon as it cools and hardens, which can take anywhere from a few hours to a few days.
The production of asphalt requires bitumen, which is a petroleum product that can release harmful fumes. Exposure to these fumes can cause negative health effects, including burns, skin rashes, throat and eye irritation, coughs, headaches, and skin cancer. Those affected by these fumes tend to be those working with the asphalt in production, construction, or maintenance.
The production and maintenance of asphalt can have environmental consequences. The following are the key environmental impacts of asphalt:
Bitumen is an essential material in asphalt because it binds the aggregate together, allowing it to harden into a durable and smooth surface for walking and driving. However, the extraction of bitumen can have negative impacts on the environment. It is the largest contributor to asphalt pavement environmental impacts, contributing around 26-80 million tons of carbon dioxide equivalent in 2020, which comes out to between 0.05% and 0.15% of global greenhouse gas (GHG) emissions.
Bitumen comes from oil sands, and extraction requires clearing large areas of land. In particular, surface mining for bitumen can lead to habitat destruction and has a history of contaminating waterways and groundwater.
Sand, gravel, and stone aggregate used in asphalt often comes from limestone quarries, which leads to varying environmental impacts, such as:
Transporting raw materials involved in asphalt can create significant carbon emissions. The distance traveled and the mode of transport can all affect how transportation impacts GHG emissions and environmental pollution.
Making asphalt is energy intensive — any process that requires the maintenance of high temperatures will necessitate higher energy input. Aggregate heating generally uses nonrenewable resources and accounts for up to 97% of the total energy consumption in asphalt production. As a result, the manufacturing of asphalt produces a high level of emissions.
Asphalt plants may also release harmful substances into the air, such as sulfur dioxide and volatile organic compounds (VOCs). These pollutants contribute to smog in urban areas and harm air quality for humans and animals.
While asphalt is incredibly strong, it is not a permanent fixture. Asphalt degrades over time, exacerbated by frequent use, temperature changes, and water intrusion. Cracking and potholes are a result of asphalt degradation and require repairs. While some cracks and potholes only need a quick patch or seal, asphalt pavements will eventually require resurfacing or replacement.
The lifespan of an asphalt roadway is only around 15 years — considering the number of roadways there are, these replacements and repairs take significant resources. The heavy equipment, often powered by diesel engines, and the waste generated from asphalt repair can take a toll on the environment.
Asphalt roads and paths require special construction techniques to mitigate their impact on the soil’s natural draining capacity. Asphalt does not absorb water, and redirecting the natural flow of water can result in soil erosion and flooding. A build up of stormwater runoff can also carry pollutants like heavy metals and oil into the waterways and potentially seep into the groundwater drinking supply.
The prevalence of asphalt as a building material also contributes to the urban heat island effect. This is a phenomenon in which urban areas tend to have higher average temperatures than surrounding rural areas because building materials like concrete and asphalt reemit the sun’s heat more than natural materials.
With a higher concentration of roads and buildings and fewer trees, urban areas can have temperatures between 1-7 degrees Fahrenheit higher than outlying areas. These higher temperatures mean it takes more energy to cool buildings and can be uncomfortable or dangerous for humans and animals.
Extending the lifespan of asphalt is a key concern for engineers, contractors, and public works officials. The investments required to maintain asphalt roads every few years are significant, and these repairs also contribute to higher emissions. FORTA has responded to this need with FORTA-FI fiber-reinforced asphalt. With a state-of-the-art blend of aramid and polyolefin fibers, FORTA-FI improves the overall performance of asphalt pavements.
By incorporating this high-tensile strength synthetic fiber blend into the asphalt mix design, you benefit from extended maintenance schedules. The fibrous materials in FORTA-FI enhance the structural integrity of the asphalt, meaning you only have to seal it every four years rather than every two.
FORTA-FI is a more eco-friendly, long-term solution to traditional asphalt. With less frequent repairs and replacements, organizations and municipalities can reduce the emissions and waste associated with asphalt production.
After extensive testing, FORTA-FI obtained an environmental product declaration (EPD). This standardized document outlines quantifiable information about a product’s environmental impact throughout its entire life cycle. Using products with EPDs offers greater transparency to inform decision-making, allowing stakeholders to ensure products align with sustainability objectives. Using concrete products with EPDs, like FORTA-FI, also enables better preparation for tighter carbon regulations in the future.
FORTA engineers have a combined 100 years of industry experience, enabling us to bring you the most sustainable construction solutions on the market. Whether you’re constructing a high-traffic roadway or need assistance for a resurfacing project, our fiber-reinforced asphalt solutions will help you pave the way for more sustainable infrastructure.
To learn more about our construction solutions, contact us today.
