Nerves of Asphalt   Asphalt Today 2006 February 2008   By Nicholas Hornyak, Ph.D., and James Crovetti
Perpetual pavement receives brain to help researchers monitor health

Jersey becomes uniform   Asphalt Today 2006 February 2008   By Rodney Garrett
State makes a commitment to smoothness on all road projects

Dry Parking   Storm Water Solutions July 2005   By Kent Hansen, P.E.
The stone recharge bed is the heart of the porous pavement. It provides temporary storage of storm water falling directly on the pavement as well as from other impermeable surfaces.

Biting into a mountain   Roads & Bridges May 2005   Mike Douglas and Gary Williams
the national trend away from new construction to the preservation of the existing highway system is requiring NDOT as well as other highway agencies to seek alternative approaches to pavement preservation that will conserve resources. Recently, NDOT pushed its CIR experience to the limit by requiring a CIR with overlay rehabilitation strategy on Rte. 207, Kingsbury Grade, near Carson City, Nev.

Just Following Policy!   Roads & Bridges October 2003
Foamed asphalt lets Ulster County, N.Y., keep its roads open to local and tourist traffic while they undergo complete recycling and stabilization as base material prior to overlay.

Polishing Monuments   Roads & Bridges October 2003   Michael L. Polak
The Asphalt Recycling & Reclaiming Association (ARRA) has just recently spent two years producing the Basic Asphalt Recycling Manual (BARM) endorsed by the Federal Highway Administration. The BARM will introduce road managers to the recycling technologies that are available today.

Sharpen Those Incisors   Roads & Bridges October 2003   Allen Zeyher, Associate Editor
Although most of the new products in this section are bigger and more powerful than their predecessors, there are still machines available for every application. This month, Roads & Bridges has gathered a sample of recent introductions of recycling/reclaiming machines and cold planers used for grinding up and recycling pavement.

Cooled and ready to serve?   Roads & Bridges September 2003   Margaret Blain Cervarich, Contributing Author
The leaders of the National Asphalt Pavement Association (NAPA) learned of cutting-edge technologies in Europe for bringing down temperatures and, during the summer of 2002, conducted a European study tour to research and evaluate three of these processes. "The impact of warm-mix technologies on the industry may be as significant as the introduction of stone-matrix asphalt and engineering controls," Peter Wilson, NAPA's 2003 chairman, commented.

Test Temp   Roads & Bridges August 2003   TransTech Systems Inc.
There was a need for manufacturers to find a more permanent solution to the tender zone problem. A couple of R&D-minded manufacturers jumped into the lead with equipment and instrumentation designed to get the job done faster.

Rolling a perfect score   Roads & Bridges August 2003   Steve Muench, Contributing Author
A group of researchers at the University of Washington are working on a first-generation 3-D hot-mix asphalt (HMA) compaction trainer called the Xpactor. The Xpactor works like a video game and allows users to operate a virtual HMA roller in a three-dimensional computer environment. The Xpactor can assist learning with any number of compaction issues including proper rolling patterns, longitudinal joint rolling and time available for compaction.

Do they all agree?   Roads & Bridges July 2003   Tom Harman, Contributing Author
As a part of the Superpave mix design system, gyratory compactors are important in defining the mix characteristics to be achieved in production. There are currently eight approved models of gyratory compactors. It is important that these devices provide consistent results from one to another, because results from contractors' mix designs are used to provide construction control and are subject to agency verification. A lack of consistency can result in substantial and needless penalties and a mutual distrust between contractors, testing firms and agencies.

Quality Education   Roads & Bridges April 2003   Bill Wilson
In January, K. Barnett & Sons and the New Mexico State Highway Department were named to an elite honor roll. The National Asphalt Pavement Association recognized work done on a five-mile stretch of I-25 with the 2002 Sheldon G. Hayes Award. K. Barnett & Sons went beyond the required rhetoric, using constructive innovation in a state that has really kept future road development in check.

Cracking the compactor code   Roads & Bridges April 2003   Steve Wilson, Contributing Author
Selecting the right roller for a particular operation does not need to be confusing, nor does it need to involve a certified mathematician to calculate countless performance values. It simply requires understanding some of the basic specifications found on most manufacturers' product sheets, such as frequency, amplitude and centrifugal force, and having a general idea of how these all relate to one another. Additionally, there is another rarely published specification known as "output horsepower."

Eyeing the surface   Roads & Bridges April 2003
Segregation may be defined as lack of homogeneity of constituents in hot-mix asphalt (HMA) pavements such that accelerated pavement distresses occur. The most common form of HMA segregation has been identified as gradation segregation. Gradation segregation is the non-uniform distribution of coarse and fine aggregate materials in the finished HMA pavements. The work described here was specifically focused on the use of laser technology to develop procedures or screening tools to determine segregated areas.

Industry marches on   Roads & Bridges January 2003   Allen Zeyher
What follows are brief descriptions of a few of the asphalt-production product announcements we have received recently. It is not meant to be a comprehensive survey of products currently on the market.

Scoring at Home   Roads & Bridges January 2003   E. Ray Brown, Ph.D.
The first two-year cycle of tests at the National Center for Asphalt Technology (NCAT) Test Track, Auburn, Ala., was completed recently. The results of this first series of tests were presented at the National Transportation Symposium at NCAT held on Nov. 13-14, 2002. Here are some of the findings.

Strongly recommended   Roads & Bridges January 2003   Bill Wilson, Editor
When the Ohio Department of Transportation worked out designs for the expansion of a 2.3-mile stretch of I-77, it originally wanted a 131/4-in. asphalt pavement over an asphalt free-draining base and 6-in. aggregate base. Northstar Asphalt, however, believed more resilience was needed to cover a seven-year warranty, and convinced officials to go with the state's first section of perpetual pavement.

Rolling on the stones   Roads & Bridges January 2003   Dave Newcomb, Contributing Author
matrix asphalt (SMA) is a strong surface for high-volume, heavy-duty roadways. Why the big interest? It's simple: * Improved performance, noise reduction, and improved safety.

A Love For the Crush   Roads & Bridges October 2002   Rick Zettler
Independence Recycling has grown into a major-league success story. From humble beginnings as a local recycle contractor with a single portable crushing and screening plant started primarily to handle demolition materials generated by its sister company, today the company employs 60, operates nine portable horizontal shaft impact crushing plants producing in excess of 3 million tons of spec product per year and services a broad customer base east of the Mississippi River.

The Common Cold?   Roads & Bridges October 2002   Mickey Cereoli
Roughly 30 years ago, Bomag pioneered some of the first cold in-place asphalt recyclers in the roadbuilding industry. This was not only a new piece of equipment, it was the introduction of a new concept. Today, several manufacturers have introduced cold in-place asphalt recycling equipment. Though credibility has been established through education and successful applications in many states and counties, understanding the process and its benefits remains the key challenge to its acceptance as a viable road reconstruction option.

Back to Being Super   Roads & Bridges October 2002
The first sustained efforts to recover and reuse old asphalt paving materials were conducted in the mid 1970s. With financial support of the Federal Highway Administration (FHWA) and technical assistance from trade associations such as the National Asphalt Pavement Association and the Asphalt Institute, more than 40 states placed demonstration reclaimed asphalt pavement (RAP projects by 1982. RAP is now routinely used in nearly all 50 states.

Do Not Throw Out   Roads & Bridges October 2002   Bill Wilson
All over the U.S., community recycling programs do not cater to anyone. The road paving business, on the other hand, is at your service. They'll set up a work zone for you, haul in a milling machine or an excavator with a concrete breaker for you, operate the heavy machinery for you and haul it away for you.

Bloodline Paving   Roads & Bridges September 2002
You just may be able to travel the country and not find a better asphalt or concrete road project executed by Haskell Lemon over the last five years. In 1998, the National Asphalt Pavement Association gave the company its trumpet treatment by honoring them with the 1997 Sheldon G. Hayes Award for work done on Oklahoma's I-40. The American Concrete Pavement Association recognized Haskell Lemon with top honors for a paving job on the Broadway Extension (U.S. 77) and Britton Road.

Sales are hot--so is asphalt   Roads & Bridges August 2002   Margaret Cervarich
The Victor facility of Rochester Asphalt Materials recently earned the Diamond Achievement Commendation for Excellence in Hot Mix Asphalt Plant/Site Operations from the National Asphalt Pavement Association (NAPA). In 1996 a developer came to the company with the idea of putting in a shopping mall that would house stores like Target and Home Depot. Rather than go through the permitting process at a new location, Rochester Asphalt Materials worked out an arrangement with the mall that allowed them to move the plant to one side of the property. Because they remained at their old location, the existing permits covered them.

Segregation Buster   Roads & Bridges August 2002   Bill Rieken
At every stage in handling aggregate and asphalt, there is a chance for material segregation to occur. With numerous opportunities for segregation to occur even before the asphalt reaches the jobsite, it does not seem quite fair that the paving crew is now challenged to lay a high-quality, smooth mat void of segregation. Fair or not, however, it is a fact of life.

Viewing the Fill as Half Glass   Roads & Bridges May 2002   Allen Zeyher
Walking on broken glass is probably a bad idea, but driving over broken glass might be a good idea if the glass is used as fill under the road. crushed glass fill is part of a $5.6 million, federally funded project driven by the need to replace a narrow three-span bridge over the Big Wood River.

Iowa’s playing field   Roads & Bridges April 2002   Bill Wilson
During its 47th annual convention in San Francisco, the National Asphalt Pavement Association (NAPA) honored Norris’ flawless execution on a 61/2-mile stretch of Route P46 with the 2001 Sheldon G. Hayes Award. It marked the second time the gold medal of the asphalt paving industry went to an Iowa contractor.

Full cooperation   Roads & Bridges April 2002   Margaret Cervarich
The Big I Reconstruction Project in Albuquerque, N.M., involves more than 2 million cu yd of dirt, 610,000 tons of hot-mix asphalt (HMA) and 165,000 cu yd of concrete. And all of it is being used to rebuild two interstate highways (I-25 and I-40) that happen to cross each other in the middle of a busy metropolitan area.

A Thick Dry Stake   Roads & Bridges January 2002   Daniel Brown
States investing more money into asphalt's perpetual pavement

Homemade asphalt   Roads & Bridges January 2002
Contractors are starting to see the benefit of producing their own mix

Hard Doesn't Mean Stale   Roads & Bridges October 2001   Bill Wilson
New cold in-place recycling claims to strengthen asphalt pavement

Flying for business   Roads & Bridges September 2001   Margaret Blain Cervarich
In an effort to minimize traffic disruptions, Des Moines speeds through repaving project

Roll with it   Roads & Bridges August 2001   Bob Miller
Contractors need a close relationship with compaction equipment

Pick up the tempo   Roads & Bridges August 2001   Allen Zeyher
Higher vibration frequency is crucial in asphalt compaction

Experiencing good fortunes   Roads & Bridges May 2001   Bill Wilson
Two years after receiving millions, Thompson-McCully wins Hayes Award
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Foam on Bottom   Roads & Bridges May 2001   Blair Barnhardt
States like Georgia find inexpensive base for asphalt rehab
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Unmasking the problem   Roads & Bridges May 2001   David S. Klen
BP Amoco cleans industry with low fuming asphalt
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Fighting A Beating   Roads & Bridges January 2001   Dan Brown
Congested hot-mix asphalt intersection in Maryland shows little signs of wear-and-tear
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Hot Rod Asphalt   Roads & Bridges January 2001   Rodney Garrett
Contractor makes the right moves during paving process at Kansas City Speedway
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ASPHALT ANSWERS   Roads & Bridges December 2000   Prithvi S. (Ken) Kandhal, P.E.
Restricted Zone in Superpave Specification
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Announcing It To The World   Roads & Bridges September 2000   Dan Brown
New test track and research center ready to produce vital information

A Growing Need   Roads & Bridges September 2000   Dale Decker, P.E.
As Superpave technology takes off, industry knowledge continues to progress

Making Sure They Match   Roads & Bridges September 2000   Chuck Deahl
Superpave mixes must meet certain compaction specs, which could be a challenge

ASPHALT ANSWERS   Roads & Bridges May 2000   Prithvi S. (Ken) Kandhal, P.E.
Improving the quality of pavement performance

Philosophical Asphalt   Roads & Bridges May 2000   Larry Flynn
The Greek philosopher, Aristotle, was never a part of a hot-mix asphalt (HMA) paving crew and never worked at a hot-mix plant, but his teachings are applicable to the field, at least in the case of Shalimar, Fla.-based Couch Construction LP. The philosopher’s thoughts on excellence in association with other ideas on courage, humility and nobility served as guiding principles by which the employees of the company have lived in recent years.

Rolling with the punches   Roads & Bridges March 2000   Bill Wilson
All other things being equal in the asphalt compaction process, an increase in the ground speed of a vibratory roller can translate directly into an increase in profit or decrease in expense, depending on which side of the equation you are on. But there’s one catch–anyone understanding the theory of vibratory compaction knows that the above statement can only be true with a corresponding increase in vibration frequency.

ASPHALT ANSWERS   Roads & Bridges January 2000   Prithvi S. (Ken) Kandhal, P.E.
Detecting and quantifying segregation

ASPHALT ANSWERS   Roads & Bridges October 1999   Prithvi S. (Ken) Kandhal, P.E.
Measuring bulk specific gravity

A Hot, In-place in the Sun   Roads & Bridges October 1999   by Larry Flynn
Hillsborough County, Fla., takes a torch to its road maintenance costs by making hot-in-place recycling of asphalt pavements a key element in its program.

Chewed up, churned out, back on road   Roads & Bridges October 1999
Reclaimed concrete, asphalt returned to road proving to be a time and moneysaver

Pressing the hot button issues   Roads & Bridges October 1999   by Cliff Mansfield
In the second of a two-part series, ROADS & BRIDGES looks at the future of asphalt paving plants.

A HMA Plant Milestone   Roads & Bridges September 1999
Florida company installs its own facility to meet demands of the Superpave movement.

Fast, Fast, Fast . . . Fast Vibrations   Roads & Bridges August 1999   Bill Wilson
Superpave technology has compaction rollers shifting into high gear

ASPHALT ANSWERS   Roads & Bridges May 1999   Prithvi S. (Ken) Kandhal, P.E.
Superpave’s restricted zone

RAP Mix Design for HMA Pavements   Roads & Bridges February 1999   Dale Decker
The second in a three-part series on the use of reclaimed asphalt pavement (RAP) in hot-mix asphalt (HMA) focuses on RAP mix design techniques. In March, the handling of RAP in the HMA facility and placement and performance issues will be addressed.

Superpave Super Projects   Roads & Bridges January 1999   David Banasiak
Each year, the National Asphalt Pavement Association recognizes construction excellence through its paving awards programs; projects nominated stress smoothness while using Superpave mix design.

State of the Practice for Use of RAP in Hot-mix Asphalt   Roads & Bridges January 1999
This is the first in a three-part series of articles on the use of reclaimed asphalt pavement, known as RAP, in hot-mix asphalt (HMA). The articles are excerpted from a report published by the National Asphalt Pavement Association on the state of the practice of the use of RAP. In this installment, we’ll examine the generation and handling of RAP materials. In February, mix design techniques will be discussed. In March, the handling of RAP in the HMA facility and placement and performance issues will be addressed.

The Smooth - Quiet Pavement   Roads & Bridges January 1999   Dale Decker
Studies have shown that, to the motoring public, smoothness is chief among the factors of what makes a good roadway pavement; but achieving such a pavement is not as easy as it may sound.

ASPHALT ANSWERS   Roads & Bridges October 1998   Prithvi S. (Ken) Kandhal, P.E.

Maintaining High Performance Levels   Roads & Bridges September 1998
This is the third of four articles excerpted from Special Report 181 Report of Customer Oriented Highway Construction Workshop published by the National Asphalt Pavement Association. The first two installments appeared in the June and August 1998 issues. The fourth installment on construction operations will appear in October.

Compaction Rollers and Testing Equipment Work to Provide a Quality Road Surface   Roads & Bridges August 1998
Designed and used to compact material for any number of applications, compaction rollers densify material through the application of static force or dynamic force combined with static force. ROADS & BRIDGES will provide an overview on asphalt compactors and the different size and type of machines that are capable of handling a variety of applications. In addition to asphalt compactors, density gauges, gyratory compactors and other asphalt testing equipment will be reviewed.

Superpave Goes to School   Roads & Bridges June 1998
Five Indiana universities are incorporating the Superpave asphalt binder and mix design method into their curricula.

ASPHALT ANSWERS   Roads & Bridges May 1998   Prithvi S. (Ken) Kandhal, P.E.
Intersection rutting rectified

Quality Asphalt Paving: Easy as A + B   Roads & Bridges May 1998   Larry Flynn
Oklahoma contractor and DOT are recognized for producing and placing the best asphalt pavement in the land; project marks first for state in use of A + B bidding and polymer modification.

Superpave: At Last a Success   Roads & Bridges March 1998   D.R. Turner
The Florida DOT works with a contractor to make Superpave a success

Oklahoma Contractor Claims Top Asphalt Paving Award   Roads & Bridges March 1998
Oklahoma City's Haskell Lemon Construction receives asphalt paving's highest honor for reconstruction project; Kansas and Tennessee contractors are finalists.

Superpave Binder Specs Get Refined   Roads & Bridges March 1998   Laurand Lewandowski, Ph.D.
To better understand the development of Superpave and polymer-modified asphalt specifications, one most look at the past, present and contemplate the future

A Material Engineer's Perspective: Field Compaction of Superpave Mixtures   Roads & Bridges February 1998   Michael K. Prather
Superpave has made many improvements to the durability of asphalt cement concrete pavements, however, as with any new system, allowances must be made for the unexpected changes.

Field Management Key to Superpave Compaction   Roads & Bridges February 1998   Charles W. Deahl
The Superpave mixes can be compacted productively; however, it is a learning process that involves good field management.

ASPHALT ANSWERS   Roads & Bridges January 1998   Prithvi (Ken) Kandhal, P.E.
Project studies longitudinal joints

Passing the Torch   Roads & Bridges January 1998   Dale Decker
As the Superpave binder and mix design process moves from research to implementation by the year 2000, the industry is learning from its successes and problems.

Workshop Teaches Proper Asphalt Recycling   Roads & Bridges October 1997   Prithvi (Ken) Kandhal P.E.
Recycling of existing asphalt pavements for pavement rehabilitation or reconstruction has many advantages

Battling Segregation in Asphalt Paving   Roads & Bridges September 1997   David Banasiak
New machine helps fight hot-mix asphalt segregation on paving job in Creve Coeur, Ill.

Compacting for Superpave Success   Roads & Bridges August 1997   James A. Scherocman, P.E.
A lot has been said about the Superpave binder specs and mix designs, but what about compaction of the mix once it's laid? Our two-part series addresses key issues.

Wisconsin Demo Explores In-place Asphalt Rehabilitation   Roads & Bridges June 1997   Daniel C. Brown
New technology is making the use of foamed asphalt a cost-effective alternative for road rehabilitation projects.

New Developments to Aid Superpave   Roads & Bridges May 1997   Gary Henderson
The Superpave system. We hear it mentioned at meetings, we read about it in magazines and newsletters, and we discuss it in the office. Yet what's the bottom line? Where are we right now in the transition to this performance-based asphalt mix design system?

Superpave Volumetric Mix Design   Roads & Bridges May 1997   Prithvi "Ken" Kandhal, P.E.

Ohio Ushers in Superpave Use with First Project   Roads & Bridges May 1997   Ed Longville
Contractor utilizes in-line blending of SBR Latex to manufacture performance-graded binder specified for Ohio's first Superpave project

Quality of Cold-Mix Asphalt Deserves Attention   Roads & Bridges May 1997   Michael Pemberton
Today, more municipalities and other users of cold-mix asphalt patching materials are looking for suppliers who offer an added measure of quality. However, defining what constitutes quality in exact terms is not an easy task.

Superpave Use Spreads in Iowa   Roads & Bridges February 1997   Renee White
The first Superpave project in Iowa took place in Des Moines two years ago; since then more projects have followed.

Hot-Mix Asphalt Producers Monitor Profitability Through Benchmarking   Roads & Bridges February 1997   Scott Humrickhouse and Carol Edwards
Benchmarking is a powerful management tool that enables hot-mix asphalt producers to monitor and compare critical factors that impact the profitability of their operation. It's a mechanism that allows senior management and plant operators to establish improvement targets in cost to produce per ton.

Hotter Than Georgia Microsurfacing   Roads & Bridges December 1996
Microsurfacing technique paves way for Atlanta's Olympics crowds; Fast-track project calls for quick action on part of the contractor