You are here

Asphalt

Welcome to the Asphalt Channel, a special feature that provides the user an in-depth look at the hot-mix asphalt industry.  This section offers several areas to explore: product spotlights, article archives, related case studies, related video and product/supplier contact list.   The product spotlights contain information and photos of equipment relevant to the industry.   The article library contains all stories related to asphalt roads pulled from the rich archives of Roads & Bridges magazine and our Asphalt Today supplement magazine.

Article May 05, 2015
Life-cycle cost analysis (LCAA) is used in many industries, including the transportation industry, to make rational decisions regarding large investments.   LCCA is designed to factor in the initial and recurring costs throughout the life of the investment to select the most cost-efficient...
Article May 05, 2015
Steep pavement-edge drop-offs are more common on rural two-lane roads with unpaved shoulders, but also occur on roads with paved shoulders.   Typically, the unbound material at the pavement’s edge settles and erodes over time, creating a drop-off and increasing the difficulty drivers face in...
Article May 05, 2015
In 2007, the California Department of Transportation (Caltrans) made the decision to answer the question: How does warm-mix asphalt (WMA) affect performance of asphalt concrete mixes?   This decision began the first phase of a comprehensive study into the use of WMA for Caltrans by the University...
Article May 05, 2015
Commerical and small municipal paving contractors often find themselves between a rock and a hard place.   Most take pride in being nimble and flexible, selling on the advantage of quickly servicing the needs of the customer more so than the larger, more established asphalt producer/contractor in...
Article May 05, 2015
Because of its many benefits, warm-mix asphalt (WMA) is becoming increasing popular with producers, paving crews and specifying agencies.   The goal with WMA is to produce mixtures with strength, durability and performance characteristics similar to or better than hot-mix asphalt (HMA) using lower...
Article May 05, 2015
Chip seal and microsurfacing are two of the main preventive maintenance treatments used in Ohio for the preservation of asphalt-surfaced pavements.   The primary intent in using these two treatments is to slow pavement deterioration and defer costly rehabilitation. In Ohio, chip seal is a sprayed...
Article May 04, 2015
Thin-lift overlays are quickly emerging as a preferred alternative to other road-surface preservation treatments.   In Oregon, thin lifts are typically made up of 3⁄8-in. (9.5-mm) mix installed at a thickness of 1 to 1.5 in. These overlays are proving to be more economical than other surface...
Article May 04, 2015
Crack sealing has been used as a very cost-effective method of pavement preservation for decades.   Crack sealants reduce moisture and debris infiltration into the pavement structure, thereby, improving pavement performance.  During the life of most asphalt concrete pavements, overlays are placed...
Article May 04, 2015
The use of warm-mix asphalt (WMA) has grown rapidly in the short time it has become a familiar acronym in the U.S. In fact, the Ohio Department of Transportation (ODOT) placed 2.8 million tons of water-injected WMA in 2011.   But, ODOT’s WMA work has not advanced without concerns, questions and...
Article May 04, 2015
As the need grows for new rehabilitation methodologies to improve the performance of hot-mix asphalt (HMA) overlays on top of existing concrete pavement, saw and seal offers a cost-effective solution to the reflective cracking problem when properly constructed.   Reflection of cracks in HMA...
Article May 04, 2015
Since asphalt roadways began to appear in the U.S. in the mid-19th century, Americans have been seeking to enhance the quality of their roads.   Improved pavement performance has long been the goal of the modern asphalt industry. But even as pavement designs continue to advance, our highway...
Article May 04, 2015
NAPA is the trade association charged with representing the asphalt-pavement industry before the U.S. Congress and federal regulatory agencies. Our activities in Congress are guided by two principles: First, we support a robustly funded, multiyear highway bill; also, we act as our industry’s...
Article May 04, 2015
Around the country, agencies struggle with tight budgets and contractors struggle with unpredictable material prices in a competitive market.   This is not good for our nation’s highways—they continue to deteriorate—or for our economy. But it has had one benefit: It has created strong partnerships...
News April 29, 2015
Designers, contractors and government officials can submit their top road projects to be considered for the 2015 Roads & Bridges' Top 10 Roads list. This list receives media attention all over the U.S. To submit, go to www.roadsbridges.com, click on the Top 10 Road logo and then hit the...
Article April 28, 2015

Figure 2. APA specimens before loading

Hot-mix asphalt (HMA) is the most commonly used material for asphalt-paving applications.   It is produced by drying the aggregates prior to mixing with the heated asphalt binder. The temperature at which this material is produced generally ranges from 300°F to 325°F for unmodified asphalt binders...
Article April 28, 2015

VDOT’s modified EP-5 epoxy overlay waterproof membrane was placed on the travel and passing lanes of the SBL bridge on I-85.

Overlays are placed on bridge decks to reduce infiltration of water and chloride ions and to improve skid resistance, ride quality and surface appearance.   Hydraulic cement concrete (HCC) overlays used in Virginia include latex-modified concrete (LMC), first used in 1969, 7% silica fume concrete (...
Article April 28, 2015

In all, 232,000 tons of asphalt base and surface mixes were paved and compacted along the 6.2-mile stretch of Kentucky’s Highway 60.

The stretch of U.S. Highway 60 connecting Lexington to Kentucky’s capital, Frankfort, carries many high-profile commuters.   State lawmakers take the route for their work; celebrities can be spotted on their way to take in horse racing; and “many Kentucky Transportation Cabinet employees travel...
Article April 28, 2015
In the mid-1990s the Louisiana Department of Transportation and Development (LADOTD) revised its hot-mix asphalt (HMA) mixture specifications.   Some of those major changes included requiring larger nominal maximum aggregate size in its aggregate structure and significantly reducing the amount of...
Article April 28, 2015

If you speed up the drum and have the proper flights in the drum, you prevent the aggregate from dropping prematurely. This creates a better aggregate veil, which allows it to be heated better by the dryer. The technique translates directly to the roadway.

Change is scary. But so are car accidents.   Along a stretch of U.S. 264 in central North Carolina, drivers had an extremely high risk for hydroplane accidents. To address the most dangerous areas, the North Carolina Department of Transportation (NCDOT) patched sections of the road with open-graded...
Article April 28, 2015
Limited dollars must be spent wisely, and public agencies must ensure they are giving their customers—the driving public—the best performance possible for their tax dollars.   We in the asphalt industry are full partners in this effort. Last year, the National Asphalt Pavement Association (NAPA)...
Overlay Init