(Photo: Big River Industries)

Daily rains, high tides and south winds of hurricane caliber had taken their toll on Louisiana Highway 3147, a coastal marsh state highway in Vermilion Parish, Louisiana. Located along the Gulf of Mexico, the road was disintegrating under the constant exposure to water, causing wash outs and soft spots. With daily maintenance needed to allow motorists to safely travel the posted speed, the state decided it was time for improvements.

The Louisiana Department of Transportation and Development (DOTD) ordered a 12-inch limestone base and a three-course surface treatment for the five-mile stretch of road. A flexible pavement was chosen for the site, considering the coastal marsh climate and the flexibility of the existing aggregate surface. The three-course surface treatment included the use of CRS-2P, a cationic rapid setting type of emulsified asphalt modified with the addition of polymers, and expanded clay lightweight aggregate (LWA), a product from nearby Big River Industries, Inc., in Erwinville, Louisiana. In three applications, CRS-2P was sprayed onto the new asphalt road surface and covered with a layer of expanded clay LWA. Finally, the road surface was rolled using a pneumatic rubber tire roller to embed the aggregate into the asphalt.

“The three-course treatment used two applications of size 2 LWA, with a smaller, size 3 expanded clay LWA applied over top to help fill in any gaps in the size 2 aggregate,” said Terry LeJeune, a representative for Big River Industries. “This provides more skid resistance and makes the road safer, which is important under the wet conditions motorists regularly experience on this road.”

Applied by subcontractor P.R. Parker, Co., this was the first three-course treatment the company did for the state, and one of the first company president Phillip Parker says he knows of being installed in Louisiana in at least 10 years.

“Louisiana has put a lot more money into road preservation using chip seal,” Parker said. “This surface treatment seals the surface of the existing pavement to keep water from infiltrating into the base and subgrade, which would cause the road to fail. Water acts as a lubricant on the soil and base below, and allows it to move, and that’s what causes rutting and other base failures. I believe the state chose a three-course chip seal treatment for the road along the coast because it does have more water on it than other roads. Chip seal keeps water out better than any other surface in highway construction.”

The Material

A close-up shows the highway’s three-course surface treatment that included the use of CRS-2P, a cationic rapid setting type of emulsified asphalt modified with the addition of polymers, and expanded clay lightweight aggregate. (Photo: Big River Industries)

Expanded clay LWA, produced by Big River Industries, has been used widely on all types of asphalt roads in the past 40 years, exceeding more than 3,000 miles of asphalt pavement annually. LWA has been used in more than 20 states because installation costs are competitive with, and LWA offers many advantages over, ordinary aggregates.

The quality of expanded clay LWA results from a carefully controlled manufacturing process. In a rotary kiln, selectively mined clay is fired in excess of 2,000 degrees F. The clay expands, cools and is then processed to specified grading. The result is a high-quality, lightweight aggregate that is inert, durable, tough, stable, highly insulative and free-draining, ready to meet stringent structural specifications.

Routinely, a 20-percent longer life can be expected due to the LWA-asphalt bonding improvement. Expanded clay LWA has an ionic affinity for bonding to asphalt because of its surface charge and its rough, ceramic microsurface texture. In addition, it can be easily wet down before application to the asphalt to eliminate dust from adhering to the particles and preventing bonding, unlike natural aggregate, which is coated with dust.

According to Harold “Skip” Paul, director of the Louisiana Transportation Research Center, expanded clay LWA performs as well as any other aggregate, based on surveys evaluating LWA and other aggregate applications on roads over a 10-year span. “In fact,” Paul said, “It may even perform better in some cases.” Based upon these findings and its systematic approach to LWA manufacturing, Big River Industries is positioned to compete with traditional aggregates in cost and availability for shipments.

Safety First

Expanded clay LWA road surfaces provide skid resistance, wet or dry, which is maintained throughout the road’s service life because of LWA’s rough micro surface texture. Natural aggregates polish, becoming slick under the wearing action of traffic. Conversely, expanded clay LWA is a ceramic material that is porous throughout, so as it wears, fresh interior cells with rough edges are continually exposed.

“Think of it as a sponge, which has holes throughout its thickness,” explained Jeff Speck, vice president of sales and marketing for Big River Industries. “If you cut the sponge in half, you still expose the holes. Expanded clay LWA is surrounded by a ceramic matrix that is hard. Those holes and the surface together expose a rough texture. It never polishes because it is not a solid particle, whereas limestone is a solid particle.”

Under a number of friction tests conducted by researchers at the Louisiana Transportation Research Center, Paul said there was no comparison to LWA. “Lightweight aggregates had the highest friction numbers; they scored 20 to 30 points above any other material out there,” Paul said. “It is the safest material from a friction perspective.”

Chip seal projects using expanded clay LWA also receive fewer driver complaints because flying particles caused by passing vehicles are decreased and far less dangerous, due to the small size and lightweight density of the material. LWA’s ionic bond to the asphalt adheres the aggregate to the road, thus windshield damage claims are practically eliminated, reducing liability and helping to stretch road building budgets.

An Economical Option

One passing challenge during the project was a herd of cattle being driven down the road by some horsemen. Since work was halted for a short period, the crew took a few photos as the herd waddled past. (Photo: Big River Industries)

At one point during the three-course chip seal treatment on Louisiana Highway 3147, Parker and his crew had to stop working because a herd of cattle were being driven down the road by some horsemen. Aside from those unexpected visitors, the remote location of the job proved to be the main challenge, with a pontoon bridge to maneuver across and special considerations to get equipment to the site, Parker recalled. With little access to crushed limestone in the vicinity and the ready availability of expanded clay LWA, the choice of which aggregate to use was clear.

“An advantage to using the lightweight material was the freight in trucking costs,” Parker said. “It performs as well as any other materials, and it is a whole lot less expensive to haul to the job, and in Southern Louisiana, where there is no natural stone, it is a major concern.”

Expanded clay LWA is typically half the density of natural aggregate, resulting in one ton of LWA yielding twice the volume of natural material. This translates to half of the costs to haul LWA, resulting in fewer drivers and trucks being assigned to the project, as well as less disruption to motorists.

“We can haul twice as much LWA in one load as hard crushed stone, from an economic and environmental standpoint, you’re burning a lot less diesel fuel to get material there when you use lightweight.” Parker said. “I recommend using LWA whenever geography makes cost a major issue and when skid resistance is a necessity.”

LWA offers lower direct and indirect costs over the service life of the road, and for this reason more state and local transportation departments are specifying the use of LWA. For example, asphalt roads need maintenance about every five years, according to LeJeune. Adding a chip seal treatment to an asphalt road prevents cracking, rutting and other common problems. “It is a low-cost alternative to applying a new hot asphalt mix overlay,” he explained.

Also according to LeJeune, the key to a successful chip seal maintenance treatment is to take care of it before roads are too far gone. “Once the big 1/2-inch alligator cracks set in, it doesn’t do any good to chip seal because it’s not designed to fill large cracks or seal patches. For what you would spend on a mile of hot mix asphalt road, you could lay down five miles of chip seal.”

With the success of Louisiana Highway 3147 coming on the heels of the research conducted by the Louisiana Transportation Research Center, it seems likely expanded clay LWA will become a commonality on other roads in the region and other parts of the country.

To learn more:
Big River Industries: bigriverind.com
Louisiana Transportation Research Center: ltrc.lsu.edu

About the authors: Don Eberly is president / CEO of Eberly & Collard Public Relations, specializing in public relations for businesses in the Design / Build, Construction, Horticulture, and Landscape Industries. Laura Drotleff is a writer for the firm. They can be reached through eberlycollardpr.com.

The webinar, titled “SR500 NHI Innovations: PaveSuite, Transforming Pavement Data into Informed Decision Making,” will take place as part of FHWA’s National Highway Institute (NHI).

PaveSuite is a demonstration product from the American Association of State Highway and Transportation Officials’ (AASHTO) Technology Implementation Group (TIG).

The webinar will focus on two of PaveSuite’s four new pavement evaluation technologies:

1. Automated Faulting Method: Software that detects joints and estimate faulting in jointed concrete pavement by using a high-speed inertial profiler.

2. Automated Cross-Slope and Drainage Path Method: A technology that allows pavement engineers to effectively identify roadway areas with a high likelihood of hydroplaning with an end goal of producing alternative corrective actions.

Florida Department of Transportation (FDOT) Pavement Engineer James Greene will moderate the webinar. Speakers include FDOT Pavement Evaluation Engineer Abdenour Nazef and Applied Research Associates Pavement Engineer Alex Mraz.

Click here to register for the webinar.

Ray LaHood

Representative Jehan Gordon-Booth (D-IL) has introduced legislation to rename a stretch of Interstate 74 in Springfield, Illinois, after outgoing Secretary of Transportation Ray LaHood, who has also served as an Illinois congressman, PJ Star reported.

The proposed legislation, House Joint Resolution 35, would rename the 6-mile stretch of I-74 from the Murray Baker Bridge to the Sterling Avenue exit as the Ray LaHood Highway. LaHood played a major role in the reconstruction of the roads along the stretch during the Upgrade 74 project that ran from 2002 until 2006.

The measure is in the House Rules Committee. It must be considered by both chambers.

The robotic tool, created in partnership with Rutgers University as part of the Long-Term Bridge Performance (LTBP) Program, is expected to save time and money during inspections. The robot uses imaging technologies similar to x-ray technlogies to scan the infrastructure and see the interior without damaging the deck.

FHWA is launching to technology on 24 bridges in Virginia, Maryland, Delaware, New Jersey, Pennsylvania, West Virginia and Washington, D.C. The agency plans to implement the robot on up to 1,000 bridges in the U.S. within the next five years.

Automatic braking systems use cameras or radars to detect surrounding objects such as pedestrians or oncoming traffic and apply brakes as needed when the driver fails to do so.

NHTSA already requires cars with electronic stability control to be outfitted with the technology. The new mandate would likely require or suggest all cars include the systems.

A Jalopnik report suggests requiring systems for use in slow-moving traffic, like Volvo’s “City Safety” system, that can be turned off when necessary.

The video below offers a demonstration of Volvo’s City Safety system.

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Strickland said NHTSA will do more research on the systems before making a decision about a mandate. The agency is expected to work on a decision later this year.

(Photo: Emily Saunders / Flickr)

A lot of orange traffic lights in Florida don’t last as long as they used to.

And that has stirred up a hornet’s nest. Are shorter orange light times just there to make money via red light cameras (RLC)? Do they risk intersection safety to make that money? Do they punish safe drivers unfairly? Or, is it a non-issue as the light-shorteners argue.

As Florida Today reports, “A subtle, but significant tweak to Florida’s rules regarding traffic signals has allowed local cities and counties to shorten yellow light intervals, resulting in millions of dollars in additional red light camera fines.”

The change was made at key intersections, “specifically those with red light cameras (RLCs),” says the report.

The National Motorists Association (NMA) points out that RLCs are a for-profit business between cities, camera companies and the state. James Walker, executive director of the nonprofit NMA says, “The (FDOT rule-change) was done, I believe, deliberately in order that more tickets would be given with yellows set deliberately too short.”

Federal guidelines, state and local best practices and a host of calculations specific to a given intersection are involved here; orange light times are not just made up by a guy with a laptop watching cars go by.

There seems to be no definitive right or wrong case made yet in Florida about the shorter orange light times. RLCs are a divisive issue, probably splitting communities roughly down the middle when it comes to arguing their pros and cons. This just adds a little more mud to the already muddy water surrounding the use of RLCs. But leaving it that way would seem to be a bad idea.

This is the Sunshine State, and we could use a little more sunshine on the use of shorter orange light times and the role of RLCs.

It is the first of four Public Outreach Sessions to be held over the next 18 months.

The DOT is required by the Moving Ahead for Progress in the 21st Century Act Section 32801 to complete the study, which will compare trucks operating within current Federal truck size and weight limits with those operating in excess of those limits.

This Public Outreach Session will allow participants to share feedback on the DOT’s intended approach for completing the study and share comments on alternative truck configurations to be evaluated in the Study.

The event is free and open to the public. It will be held as an in-person workshop, but a webinar will also be available for participants who cannot attend in person.

To register for the in-person workshop, email CTSWStudy@dot.gov, or register for the webinar here. Those unable to attend can submit comments to CTSWStudy@dot.gov.

To view a copy of the transcript and summary of the discussions after the session has ended, click here.

(Photo: Jalopnik)

What’s the best way to catch the attention of drivers and alert them to stop? Use a giant water curtain with a projection of a stop sign.

According to Jalopnik, Sydney, Australia, began installing the water curtains six years ago in response to costly damages and delays caused by oversized trucks crashing into low overhead tunnels.

News 10 reported that truck drivers ignored previous warning signs, including flashing lights. However, the water curtains seem to catch their attention.

Laservision, a light show company in Australia, worked with the city to install the water curtains in 2007.

Check out the video below to see the water curtain in action.

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Anthony Foxx

The Senate Commerce, Science and Transportation Committee will hold a confirmation meeting on May 23 for President Obama’s Secretary of Transportation nominee, Anthony Foxx, The Hill reported.

Obama nominated Charlotte, North Carolina, Mayor Foxx last month. Foxx would replace outgoing Transportation Secretary Ray LaHood.

If the Transportation Committee approves Foxx, the full Senate will need to approve him as well before he can take office.

A road in Naperville, Illinois, undergoes construction in 2009. (Photo: Michael Kappel / Flickr)

At a time when funding for roads and bridges–what there is of it–is squeezed to the maximum (a situation that isn’t likely to change any time soon) comes an unsettling new report.

Check out this lead paragraph from a story the Chicago Tribune published this week:

“Less than half of the money that the state [of Illinois] has spent from its road fund in the last two years actually went to pay for direct construction costs, according to a report issued Tuesday.”

The Trib also points out that in eight of the last 10 fiscal years, less than half of road fund expenditures went for direct road construction costs, which mainly consist of highway construction and improvements, architectural and engineering fees and repair and maintenance. The rest, in this case and those other cases, went to cover salaries at the Illinois DOT, bond debt payments and other non-direct costs.

Shouldn’t we expect some more efficiency in the use of tax dollars? It has to be conceded that “non-direct” costs are a fact of life and are as essential to transportation infrastructure construction and maintenance as direct costs. But is fifty cents on the dollar the best we can do? Yes, this is Illinois and that state’s situation won’t be mirrored anywhere else.

As we push harder and harder for more funding, as reauthorization comes racing down the road at us, the need to put as much funding as possible to work creating jobs and working on construction projects is paramount.

As a kick starter, why not put a little pressure, maybe through your local news outlets, on your transportation authority and have them tell the public what percentage of their funding goes to direct costs and where the rest of it goes. This should all be public information.

Accountability in government agencies (such as DOTs) is not just telling us what they are doing; it includes a responsibility to do the most with every tax dollar collected. If something like fifty cents on the dollar going to direct costs in our industry is the best we can expect, so be it. But is it really the best we can do?