Paving the Future of Asphalt

For anyone but an asphalt technician, hearing about the “latest technology” might bring to mind QDEL TVs, connected cars or metaverse gaming. But while anxiously awaiting the next edition of Asphalt magazine, the paving aficionado’s mind might instead be drawn to telematic capabilities, perpetual pavement designs and nanotechnology. Wait ... what? Nanotechnology? In the paving business? Read on.

The Way We Were

Asphalt paving has been the surfacing of choice in road construction for the last 100 years. Like most technology, it has seen vast improvements in functionality, efficiency and ergonomics over time. Also like most technology, the greatest strides have taken place within the last decade, with even more stunning advancements right around the corner.

It hasn’t been that long since site preparation was done with a transit and a plumb bob, asphalt removal was accomplished with a walk-behind road saw and operators sat on hot, body-rattling, smelly machines for hours on end. But it got the job done for decades because it was cutting-edge technology at the time. Small incremental improvements were made over the years, especially after World War II when the Marshall system of mix designs was introduced. As modern traffic continued to put a crushing load on the country’s roads, intense effort was invested in developing better mix designs.

A new problem emerged in the mid-1970s when the Arab oil embargo led to skyrocketing fuel prices and block-long lines at the gas pump. Household recycling was becoming popular, but the paving industry began to see it as a necessary practice to cut fuel costs. Whereas aged asphalt pavement had been considered waste material and sent to the landfill, reclaimed asphalt paving (RAP) became a valued product, stockpiled and used as an inexpensive road base. During this same time, the cold-milling machine was refined. These high-horsepower asphalt grinders became an integral part of the rehabilitation process. Today, RAP is commonplace, and asphalt pavement is the nation’s most widely recycled product.

In the early 1980s, the industry tackled a major issue with traditional asphalt paving and binders: rutting. The nation’s highways were deteriorating to crisis levels. This problem, along with water sensitivity in asphalt mixtures, transverse cracking and aging, led to the formation of the Strategic Transportation Research Study Committee in 1983. After years of development, Superpave, a performance-based asphalt mix design method, was introduced in 1993 as part of the Strategic Highway Research Program. By implementing three mechanisms — asphalt binder specifications, a volume mix design and analysis system and a mix analysis testing procedure — the program dramatically increased highway longevity. Superpave is still in use today and continues to be refined.

Here and Now

The industry continues to develop ever-improving iterations of perpetual pavement, a type of asphalt pavement designed to last 50 years or longer without major repairs. In addition to advancements in hot mix materials, the equipment used to lay it has vastly improved, with many innovations filtering down from highway projects to commercial applications.

One example is the screed paver. Though used since the 1930s, screed pavers traditionally depended on diesel or propane for heat, making uninterrupted mat-laying impossible. Electrically heated screed pavers, in use since the early 1990s, produce continuous heat via an onboard generator powered by the paver itself. Eliminating the downtime spent refueling has increased productivity and improved quality.

The digital revolution has also transformed the asphalt industry. Today’s operator stations resemble airplane cockpits with digital control boards that could excite a hardcore gamer. Computer technology has brought intelligence to paving, with global positioning systems, sensors and automation providing precision control like never before. These systems adjust to varying conditions, optimize material usage and ensure uniform results. They also minimize environmental impact with lower emissions, improved energy efficiency and the ability to incorporate recycled materials.

Telematics is another game-changer. By combining telecommunications and information processing, telematics transmits and analyzes data in real time, allowing contractors to run more efficient and profitable businesses. This technology enables dispatching of the next machine needed for a project, reassignment of equipment based on weather conditions and real-time operational adjustments. It also improves mobile fleet visibility, optimizes route planning and eliminates the need for phone-based communication.

Like every industry, asphalt paving has been reshaped by technology. But upcoming innovations would have seemed like science fiction when the industry began in the late 1800s.

To Infinity and Beyond!

Buzz Lightyear would definitely be excited about where the industry is headed in 2025. Many revolutionary ideas are on the horizon, and some are already in limited use. A few still in the research-and-development stage are generating as much anticipation as the next iPhone release.

• Energy Harvesting: Imagine roads that generate energy as vehicles pass over them, powering streetlights, charging stations or even nearby buildings. This technology involves incorporating piezoelectric materials into asphalt to convert mechanical stress into electrical energy, creating a sustainable power source.
• Smart Roads: By 2025, designated roads will be embedded with sensors and Internet of Things devices that relay real-time data on traffic flow, road conditions and maintenance needs. In major cities, these roads will provide drivers with live updates on congestion and accidents, improving safety and efficiency.
• Self-Healing Asphalt: This emerging technology aims to extend pavement lifespan and reduce costly repairs. Microcapsules containing steel fibers, oils and rejuvenators are embedded in the asphalt. When cracks appear, heat or electromagnetic fields trigger the release of these materials, effectively reversing damage.
• Enhanced AI: Artificial intelligence (AI) will play a key role in paving operations. AI will analyze vast amounts of data, guiding engineers in selecting the best asphalt for specific projects. It will also automate compaction and temperature control, with AI-equipped machines adjusting conditions on the fly to create smoother, more durable roads.
• Permeable Asphalt: Already gaining traction, this technology allows water to pass through pavement and into the ground, improving stormwater management. As climate change brings more intense rainfall, cities will turn to permeable asphalt to mitigate flooding in high-traffic areas.
• Nanotechnology: Nano-enhanced asphalt incorporates microscopic particles that strengthen the pavement’s structure, making it more flexible and resistant to weathering. Carbon nanotubes or silica nanoparticles reinforce the asphalt matrix, preventing cracks and deformation. This material is expected to become a go-to choice for highways, airports and urban roads.
• Wireless Charging: While still in its infancy, wireless charging asphalt could be a game-changer for electric vehicles. Roads embedded with charging pads would allow electric vehicles to charge while driving, eliminating the need for lengthy stops at charging stations and accelerating the shift to electric transportation.

Since the first “tar” road was laid in Paris in the late 1800s, asphalt paving has continuously evolved to improve the driving experience. Even as autonomous flying cars edge closer to reality, there will always be a need for well-designed pavement. As the asphalt industry continues to innovate, we can sit back and enjoy the ride.