Asphalt Pc
Wan Cabiness
NAPA advances the asphalt pavement industry through leadership, stewardship, and member engagement to support sustainable transportation infrastructure that paves the way for thriving communities and commerce.
NAPA is the only national trade association that serves the asphalt pavement industry. Membership is available to any asphalt pavement mix producer, paving contractor, equipment manufacturer, material supplier, equipment distributor, engineering firm, or consultant.
Stay on top of industry best practices and news by plugging in to our communication channels. From social to traditional media, we deliver information on a variety of platforms to keep you abreast of the latest issues and trends impacting the industry.
NAPA's Midyear Meeting provides enrichment and education including peer-to-peer networking, the latest national updates, and off-site activities to expand your knowledge. Explore the schedule and register today to secure your spot!
Partner with us to support the NAPAREF Road Scholars program for graduate students at NCAT. Show your dedication to excellence in teaching and research in the asphalt and roadway industry. Help us reach our goal of raising $3 million to recruit and train the industry's future!
The National Asphalt Pavement Association (NAPA) is the only trade association that exclusively represents the interests of the asphalt producer/contractor on the national level with Congress, government agencies, and other national trade and business organizations. NAPA supports an active research program designed to improve the quality of asphalt pavements and paving techniques used in the construction of roads, streets, highways, parking lots, airports, and environmental and recreational facilities. The association provides technical, educational, and marketing materials and information to its members; supplies product information to users and specifiers of paving materials; and offers educational opportunities. The association, which counts 1,100 companies as members, was founded in 1955.
Loading The GuideIn October 2019, we released the Asphalt Art Guide, produced by our pro bono consulting arm, Bloomberg Associates. The Guide features over two dozen case studies highlighting successful plaza and roadway art activations around the world, and a how-to section for cities interested in undertaking their own projects. Translations of the guide are now available to download in select languages.
In October 2019, we released the Asphalt Art Guide, produced by our pro bono consulting arm, Bloomberg Associates. The Guide features over two dozen case studies highlighting successful plaza and roadway art activations around the world, and a how-to section for cities interested in undertaking their own projects. Translations of the guide are now available to download in select languages.
The Asphalt Art Initiative grant program supports projects that demonstrate the impact of asphalt art projects and encourage cities to develop their own processes for implementing these low-cost activations effectively. Previous grant rounds supported 65 projects in the U.S. and Europe, installing from 2020-2023. Newly awarded projects in 25 cities in Canada, Mexico, and the U.S. were announced in November 2023.
Released in March 2022, the Asphalt Art Safety Study, conducted by Sam Schwartz Consulting in partnership with Bloomberg Philanthropies, found that city streets with asphalt art became considerably safer for pedestrians after incorporating art into roadway redesigns.
Asphalt art is a great way to test out street safety because it brings the community to it. You get a safer neighborhood for people to walk and you get artwork that people can enjoy and have pride in their neighborhood.
For a reasonably small amount of money, you can actually make a space much more pedestrian and cyclist friendly. And hopefully that will attract people out of cars, which is what needs to happen in order to tackle climate change.
Asphalt pavements deliver the performance that agencies, designers, owners, and drivers demand. A solution for the entire transportation network, asphalt is a completely recyclable material that delivers a safe, smooth, quick-to-construct pavement optimized for costs, community, and environment. Asphalt roads are proven solutions that work for your budget, community, and future. Paving with asphalt delivers immediate benefits today while looking out for tomorrow.
Asphalt is flexible, adaptable, versatile, customizable, and ready to meet just about every pavement need. With the option of nighttime construction and without the lengthy curing time typical of concrete, asphalt pavements offer the flexibility needed to handle all levels of traffic, and they can be maintained or repaired quickly.
The asphalt industry innovations continue to afford asphalt pavement as the most economical, efficient, and environmentally friendly pavement. Asphalt engineers are constantly innovating to make roads perform for today and the future. The asphalt industry is committed to workforce training and to scientifically analyzing pavements to ensure the best products.
Did you know that over 90 percent of the roads in America are surfaced with asphalt? For those who know the benefits of asphalt, there is no substitute. Asphalt pavement, right for America, right now and into the future.
The Role of Asphalt in Livable Communities acknowledges the momentum toward creating more livable communities and details the versatility of asphalt pavements and sustainable qualities that make it a natural source for advancing the goals of livability.
Asphalt has always been and continues to be the pavement of choice for America. This brochure discusses the benefits of the product and why asphalt is right for America, right now and into the future.
Asphalt is a mixture of aggregates, binder and filler, used for constructing and maintaining roads, parking areas, railway tracks, ports, airport runways, bicycle lanes, sidewalks and also play- and sport areas.
Aggregates used for asphalt mixtures could be crushed rock, sand, gravel or slags. Nowadays, certain waste and by-products, such as construction and demolition debris, are being used as aggregates, which increases the sustainability of asphalt.
In order to bind the aggregates into a cohesive mixture a binder is used. Most commonly, bitumen is used as a binder, although nowadays, a series of bio-based binders are also under development with the aim of minimising the environmental impact of the roads.
An average asphalt pavement consists of the road structure above the formation level which includes unbound and bituminous-bound materials. This gives the pavement the ability to distribute the loads of the traffic before it arrives at the formation level. Normally, pavements are made of different layers:
Asphalt is produced in an asphalt plant. This can be a fixed plant or even in a mobile mixing plant. It is possible to produce in an asphalt plant up to 800 tons per hour. The average production temperature of hot mix asphalt is between 150 and 180C, but nowadays new techniques are available to produce asphalt at lower temperatures. (See below).
To be able to provide the best performance to different applications, a large variety of asphalt mixes can be used. Due to the different requirements (amount of traffic, amount of heavy vehicles, temperature, weather conditions, noise reduction requirements, etc.) the respective mix used needs to have an sufficient stiffness and resistance to deformation in order to cope with the applied pressure from vehicle wheels on the one hand, yet on the other hand, they need to have an adequate flexural strength to resist cracking caused by the varying pressures exerted on them. Moreover, good workability during application is essential in order to ensure that they can be fully compacted to achieve optimum durability.
Cold mixes are produced without heating the aggregate. This is only possible, due to the use of bitumen emulsified in water, which breaks either during compaction or during mixing. Producing the coating of the aggregate. Over the curing time, water evaporates and strength increases. Cold mixes are particularly recommendable for lightly trafficked roads.
In general the asphalt layers are paved on a bound or unbound road base layer. Starting at the road surface, the first layer is called the surface course. The second layer is mostly called the binder course. The lower layers are the base courses.
The surface course constitutes the top layer of the pavement and should be able to withstand high traffic- and environmentally-induced stresses without exhibiting unsatisfactory cracking and rutting. Its main mission is to provide an even profile for the comfort of the user, while providing enough texture to ensure minimum and safe skid resistance. Depending on local conditions, functional characteristics such as skid resistance, noise reduction and durability are often required for wearing courses. In some cases, rapid drainage of surface water is desired while in other cases, the wearing course should be impermeable in order to keep water out of the pavement structure. A wide range of surface layer products can be used depending on specific requirements. Surface layers types are:
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