Concrete on asphalt upgrades farm-to-market road

Oak Crest Hill Road South East in Johnson County, Iowa, appears to be just a typical farm-to-market secondary road.

But being one of 11 Iowa highway “Stimulus” projects, worth in total $13.7 million, makes it a little less ordinary. So does its new surface.

The unbonded concrete pavement overlay of Oak Crest Hill Road from south of the city limits of Hills to the Washington County line was a nearly $1.845-million job completed by Iowa City-based contractor Metro Pavers and funded through the American Reinvestment and Recovery Act (ARRA), more commonly known as “the Stimulus.” Iowa received nearly $358 million for state and local roadway, bridge, trail and freight rail projects through the Stimulus, and Governor Chet Culver’s I-JOBS initiative kicked in $115 million for transportation projects.

The Oak Crest Hill Road concrete overlay covered two lanes and spanned approximately 5.5 miles from start to finish. The county required traffic to be maintained in one direction at all times, says Nick Kempf, co-owner of Metro Pavers.

“Because it is not a primary highway, it was not that heavily used, but [the county] still wanted to improve the road system,” says Kempf. “They tried to ‘re-profile’ it and take out some of the bumps.” And work went all the more easily, he says, because “most people along the roadway were happy to see the road improved.”

Straightforward Doesn’t Mean Easy

The Oak Crest Hill Road $1.845-million Stimulus job is a concrete overlay that covered two lanes and spanned nearly 5.5 miles from start to finish. The Iowa road was widened to provide an extra lane for bicyclists.

The overall job was fairly straightforward, says Kempf, but that doesn’t mean it didn’t have some challenges. The University of Iowa is located in Johnson County and this means a fair amount of bicyclists. As part of the project, the county asked that bicycle lanes be developed “to make it safer,” Kempf says. However, this means the road has an extraordinary width for a secondary road. “The driving lanes are 24 feet plus the extra lane to bring it up to about 34 to 36 feet,” Kempf says. As a secondary road, there were no contraction baskets, Kempf pointed out, so his team cut every 15 feet for joining.

There has been a great deal of whitetopping in Johnson County. Concrete overlays have become commonplace in Iowa as an economical means to rehabilitate the secondary road system. But for this project, rather than beginning with the removal of existing concrete, the concrete overlay was placed over an asphalt roadway. It was also poured on the shoulders that were compacted and then built up to accommodate the new bike lines. “We tried to maintain about 6 inches on the old roadbed and 8 inches on the shoulder,” Kempf says. “Our ditches had to be filled, compacted and then brought up to grade.”

The rock laid after the shoulders were compacted includes crushed recycled concrete and modified sub base. Although this wasn’t a difficult process, at times it was challenging. “We’d have weeks where the dirt contractor could not work because it was too wet,” Kempf points out. “We had to deal with the weather. We had the shoulders built up and were ready to pour on a Saturday, but then we had 2 inches of rain the night before.”

Keeping it cool

The timing of the job also presented challenges. The Oak Crest Road job was the first time Metro Pavers undertook a concrete overlay in summer. Previous overlays had been done in the fall. The summer presented challenges, but by waiting until fall, Metro ran the risk of the maturity curve taking longer. And as the day warmed up, the asphalt had to be kept cool. “We had to bring in a water truck to cool off the asphalt before we could pour on it,” Kempf explains. “We didn’t need to bring it in until between 10:30 a.m. or 11 a.m., but then we would need it all afternoon.”

According to the specs, the asphalt couldn’t be more than 90 degrees Fahrenheit because it would set on the overlay but not on the rock, Kempf points out. “We had to keep a consistent ground temperature,” he says. “We had to cool it down and stay just ahead of the paving machine. We had to have it cooled off, but it couldn’t be wet.”

Concrete overlays can be a good choice for the widening of an old pavement with narrow traffic lanes, the addition of new travel lanes – as was done with the addition of shoulders for bicyclists on Oak Crest Hill Road – or the extension of ramps, according to the University of Iowa National Concrete Pavement Technology Center’s (NCPTC) “Guide to Concrete Overlay Solutions.” (For a downloadable PDF of the guide, go to http://www.cptechcenter.org/publications/guide_concrete_overlays.pdf.) “Adequately designed and constructed widening can improve both faulting and cracking performance of the pavement,” according to the guide. “Widened slabs should be used with care with concrete overlays on stiff foundations (such as on concrete pavements) because of the increased risk of longitudinal cracking.”

NCPTC gives these rules of thumb for widening:

• Keep joints out of wheel paths, especially for bonded resurfacing.

• Tie longitudinal joints with #4 bars to prevent separation.

• Keep panels as square as possible (1.5:1 maximum).

• The width of widening rather than depth has more of a positive effect in reducing loads to the top of the existing pavement.

About the Job

Project: Concrete pavement overlay, unbonded, for Oak Crest Hill Road in Johnson County, Iowa, from south of the city limits of Hills to the Washington County line

Award from Iowa DOT: $1,845,120.47

Contractors: Metro Pavers Inc., Iowa City, Iowa

Equipment used: CMI trimmer, Power Pavers/Power Curbers 2700 slipform paver and Power Pavers/Power Curbers TC-2700 texture curing machine. “The 2700 slipform paver worked very well for the job,” Kempf says. “It’s very mobile for the kind of work we have, but it’s still heavy enough to do this kind of work. It’s a two-track machine – easy to load and easy to unload for transport.”

Concrete pavement returns to Alabama with the first concrete overlay in the state.

Hinkle Contracting is slipforming a concrete overlay on Interstate 59 in Etowah County, Ala., with its GOMACO paving train. The project features the zero-blanking band for measuring smoothness, and Hinkle’s overall average has been under a 20.

Interstate 59 through the state of Alabama was originally paved with concrete in the mid 1960s. Nearly 50 years later, the original concrete has far surpassed its life expectancy and is in need of replacement. The Alabama Department of Transportation (ALDOT) looked at different alternatives to replace an 11-mile, four-lane section of the interstate through Etowah County. They developed the alternative of an unbonded, 11-inch thick concrete overlay that would be slipformed over the existing roadway.

Concrete contractors from across the United States bid on the project, which would be the first concrete overlay in Alabama. Hinkle Contracting Corp., based out of Paris, Ky., specializes in heavy civil construction and concrete paving projects, won the bid and began work in the summer of 2010. It’s the first concrete project to be let in Alabama since the early 1980s and Hinkle Contracting had officials from across the state and the country watching the success of the project. Smoothness, edge and thickness specifications with large disincentive penalties added to the project’s challenge.

“This job has the most stringent ride specifications we’ve found anywhere in the country,” says Jim Peace, operations manager for Hinkle’s Concrete Paving Division. “This project uses the zero-blanking band and anything measuring over a 20 per tenth of a mile segment is penalty. To earn a bonus, we have to get 10 and below, with about $400,000 worth of bonus to be earned. There are $3.5 million worth of penalties available on the project if we hit between 20 and 50. If grinding is needed, it’s only allowed from 25 feet on either side of the header. If we wouldn’t be able to correct the smoothness to less than 50 with 25 feet of grinding, we’d be required to remove the entire 528-foot-long segment.

“So far we’ve paved 10.5 miles of the project’s northbound lanes and our overall average is under a 20 on the zero-blanking band.”

Two paver-mounted GOMACO GSI units were instrumental in helping Hinkled Contracting fine tune its paving operation. The GSI provided on-the-go feedback of pavement smoothness as Hinkle tweaked various aspects of its paving operation.

From the first days of paving on the project, Hinkle Contracting and their paving crew worked and experimented with different elements to create the smoothest ride possible. Different variables they looked at included types of stringline, distance between stringline rods and holders, draft of the paving mold, concrete slump, size of the concrete head in front of the paver, and all processes that can influence pavement smoothness on a concrete paving project. Hinkle equipped its two-track GP-2600 paver with two paver-mounted GOMACO Smoothness Indicator (GSI) units. The GSI units provided on-the-go instant feedback as Hinkle personnel worked to fine-tune their paving operation.

“We spent three days tweaking…tweaking the draft, the feed, the slump and more,” Peace explains. “We would make notes as we made changes and just kept tweaking until we reached where we needed to be. The instant feedback from the GSI was a good thing. It gave us the knowledge of what the concrete was doing in regards to the changes we were making. We could see right on the GSI screen mounted on the back of the paver what was happening with our concrete.”

The concrete mix design specified for the project is a very porous, very coarse mix that proved challenging to slipform. Slump averages 1.5 inches.

“We have to run the concrete at a 1.5-inch slump because of the tolerances on the project,” Peace said. “We have a one eighth of an inch edge form tolerance. If we don’t comply, we have to do removal.”

Concrete is produced on site by a mobile batch plant set up in the center of the project. The farthest haul the trucks have to make is only six miles. Federal highway regulations limit the weight of the loads the tri-axle trucks are allowed to carry. Up to 18 trucks haul 6.75-cubic-yard loads of concrete to the paving site.

The existing roadway underwent some full-depth patch repairs in areas where the concrete was in poor condition. Then, an overlay bond breaker was applied to correct cross slopes so the new concrete overlay could be applied.

The project allows no room for haul roads, so the trucks have to back up to the GOMACO PS-2600 placer/spreader and dump their load directly on the road. The PS-2600, working without the conveyor belt, spreads the concrete in front of the GP-2600 slipform paver. Baskets are placed on grade by hand every 15 feet.

The GP-2600 is paving 26 feet wide and 11 inches thick. Hand-finishing work behind the paver is kept to a minimum.

“We’re running straight edges across it, but we’re not rubbing on it,” Peace says. “If you have to rub on it, you’ve got problems that a finisher can’t fix in the slab. My philosophy is if things aren’t going right in front of the paver, there won’t be anything right behind it. You have to do your work up front correctly to guarantee a good end product.”

Concrete paving production averages 2,000 feet per paving shift. Production is limited because of the small loads the trucks are allowed to haul and the Hinkle crew always strives to keep its paver moving at a slow, steady crawl. Also, hand setting both the longitudinal and transverse baskets on grade while paving takes additional time and labor for the paving crew.

Quality of the concrete is constantly being tested and measured, both with the ride requirement and with core testing. Each 528-foot segment is cored in six different places, with 6-inch diameter cores. Cores are used to test the concrete strength and depth of the concrete, with anything over a 0.25-inch deviation in depth requiring removal and replacement.

A GOMACO T/C-600 texture/cure machine follows the paver. The new roadway is transverse tined and sprayed with a white curing compound.

“This has been both an interesting and a challenging project for us,” Peace said. “We’ve paved 528-foot segments with numbers down in the fours and fives on the zero-blanking band. Everybody is liking the ride we’re producing.”

A GOMACO Commander III is slipforming the new concrete shoulders on I-59. One will be 8 feet wide and 8 inches thick. A second shoulder will be 4 feet wide and 6 inches thick. Once shoulders are completed, the new 11-mile northbound stretch of interstate will be opened up to traffic. Then, the southbound lanes of the interstate will be closed so reconstruction can be completed.

A study three years in the making suggests bold new uses

By Tina Grady Barbaccia

In the recently-released three-year study, An Integrated Study of Pervious Concrete Mixture Design for Wearing Course Applications, mix designs and procedures for portland cement pervious concrete (PCPC) overlays for highway applications were successfully developed and field- tested in Minnesota. The pervious concrete overlay was constructed at the Minnesota Road Research Project Low-Volume Road facility (MnROAD), a cold regional pavement test track near Albertville, Minn., to determine the durability of pervious concrete as an overlay. The study, the largest and most comprehensive to date on PCPC, was conducted through Iowa State University and the National Concrete Pavement Technology Center, and authored by Vernon R. Schaefer, John T. Kevern and Kejin Wang.

The results of the tests conducted show that a pervious concrete overlay can be designed, constructed, operated and maintained. A pervious concrete overlay has several inherent advantages, including reduced splash and spray and reduced hydroplaning potential, as well as being a very quiet pavement. The good performance of this overlay in a particularly harsh freeze-thaw climate, Minnesota, shows pervious concrete is durable and can be successfully used in freeze-thaw climates with truck traffic and heavy snow plowing.

The overlay, which was nominally 4 inches thick with formed joints over the original skewed joints, was constructed in October, 2008, over concrete originally placed in July, 1993. Condition surveys of the overlay were conducted in 2009, 2010 and 2011, and according to the report, the primary distress to the overlay pavement was joint deterioration. With a minor amount of cracking, the joint deterioration is believed to be the result of the method of joint placement; saw cutting the joints would have resulted in less deterioration. The joint deterioration increased each year and is likely due to snowplow effects. The flow characteristics have been measured each year, with high infiltration results and good consistency from year to year. Operations during rain events indicate that the pervious overlay quickly removes rainwater from the pavement surface and that the water migrates lateral to the side of the pavement, indicating pervious concrete is a successful tool for mitigating splash and spray as well as reducing hydroplaning difficulties.

Testing confirmed that curing under plastic was a viable technique. The top picture shows plastic secured to keep the wind out. The final surface texture was uniform and durable.

Wet-on-dry overlays are the standard for traditional concrete overlays, says Kevern, Ph.D., LEEP AP, who developed an effective wet-on-dry mix design for pervious concrete overlays. “Pervious is normally pretty dry. There is not a lot of extra paste so it took a bit of research to produce good bonding characteristics.” In terms of performance, “the pervious concrete overlay mix isn’t being designed to be structural pavement, but we’re developing a mix strong enough to have good bonding characteristics.”

This was the first time it had been tried for a pervious concrete overlay, he says, and it also was the first wet-on-dry pervious concrete overlay in the United States. Previously, it had been tested in Belgium, The Netherlands, Japan and Australia. “This placement is wet-on-dry, which is much more difficult than wet-on-wet. Wet-on-wet has been constructed in various locations and we know it works but, is complicated and expensive to construct. Wet-on-dry would be much cheaper but, until now no one has successfully built one.”

Compaction and finishing was performed using a power roller-screed.

The project was designed to place the overlay with a slipform paver, but because of scheduling, it was placed using semi-mechanized placement. The next step is to fully mechanize placement of the pervious concrete overlay as slipform. “The next phase is to get it on an open facility with high-speed traffic,” Kevern says, although the test track undergoes the rigors of a fair amount of traffic and plowing, which is a good durability test, “We ultimately need to get it in service in a small installation before this moves to widespread use.”

If the use of these kinds of pervious concrete overlays moves to widespread use, they may have a bright future in noise reduction, particularly in urban areas. “This has half the noise generation of normal concrete,” Kevern points out. “This is where the overlay would shine – in urban areas – where there are noise considerations.” However, pervious is a filter, so an area where there is a heavy amount of dirt being tracked on and off the pavement would not be an appropriate application site for this type of overlay.

Infiltration testing showed values greater than 1,000 inches per hour without any significant decrease during the study period.

“This was an integrated study,” Kevern says. At the time we put this proposal together, we looked at all the downfalls of pervious concrete. The way the report is organized answers all of those questions.” The testing also confirmed that curing under plastic is a viable technique. “We proved that curing under plastic is a good option,” Kevern says. “The industry had been doing it, and it was hard to improve on.”

The rapid inflow meant splash and spray were minimized during rainfall events, preventing water from running off the pavement surface.

One of the big questions that was posed during the study and testing was whether air entrainment was needed. “We found that, ‘Yes,’ we need that air,” Kevern says. “The workability of pervious previously was not able to be quantified, but based on the asphalt compaction techniques we developed, we have found a way to develop workability. We developed a mix design that was strong and highly permeable. The testing in the lab found that it was equal or better than regular, good-quality concrete … and is freeze-thaw durable.” Study co-author Vern Schaefer, Ph.D., P.E., professor of civil engineering at Iowa State University, says that when developing the freeze-thaw pervious concrete, a mix design was used that put in air voids of about 20 percent. “This allows water to run through it quite easily,” Schaeffer says. “Until about five years ago, when the pavement froze it all went to hell. Now we have a freeze-thaw concrete mixture that, quite simply, works.”

Schaefer says there has been a great deal of skepticism about pervious concrete pavement overlays. The applications started out being used in parking lots. “People said it wouldn’t work on highways, but we proved it could be used on highway applications – and work,” Schaefer says. “There is still some concern about how it will hold up against truck traffic, but it is subjected to truck traffic in the current test applications and it suffers some of the damage of any overlay. The big breakthrough was the successful use of wet-on-dry applications, and it is working beyond our dreams.” v

For a downloadable PDF of An Integrated Study of Pervious Concrete Mixture Design for Wearing Course Applications, go to http://www.rmc-foundation.org/images/PvC%20Wearing%20Course%20Apps%20Final%20Report%2010-11.pdf.

PLUS: For a look at how a concrete overlay came to the rescue of an aging, secondary, farm-to-market road in Iowa, go to our digital edition at betterroads.com

Making sure the numbers add up is the first step to a successful job

That mill-and-fill job up for bid may seem the exact boost your company needs right now.

The biggest benefit for milling contractors today is flexibility of machine application, says Wirtgen America Senior Vice President Jeff Wiley. “Every job is different,” he says, “and the operator today has the opportunity to select the type of grade control system he wants to use.”

It may very well be, says Terex Roadbuilding’s John West, but there’s work to do before – or even if – you submit.

“Priority number one for the milling contractor,” he says, “you have to know what that aggregate is, in order to be able to envision what it’s going to cost you in carbide consumables and what you can project your daily production numbers to be.” A milling machine has 200-250 carbide tools, valued at about $4 apiece, he explains. “Now, are you changing those hourly or are you changing them daily? That’s a $1,000 to $10,000 variance daily. You can bid yourself right out of business here, just depending on what the severity of the aggregate is. You want to know what you’re up against before you get up against it.

“Normally, you’ll spend more on carbide tools in three years of ownership than you pay for the machine itself. It’s nothing for a contractor to spend $200,000 or $250,000 seasonally on a milling machine, just on carbide tools alone. If you can decrease that annual cost by 10 to 15 percent, that’s a huge number, particularly if you run a fleet of 10, 12 or 15 machines.”

Milling or cold planing generates recyclable or reclaimed asphalt pavement (RAP), which in turn can be used as aggregate base, stabilized aggregate base, cold-mix asphalt or new hot-mix asphalt, says Eric Baker, marketing manager with equipment manufacturer Roadtec.

On the milling side, says West, also to be considered before bidding are requirements for smoothness and pattern increasingly obligated by agencies to be tested and approved as prerequisites for project completion and contractor payment.

This will lead directly to the contractor’s cost-variable cutter pattern requirement, determined by the number of carbide teeth placed on the milling machine’s mandrel. Roadtec’s Baker explains from coarse to fine:

Excavating Pattern provides coarse 3/4-inch spacing, allowing a significant increase in production. This technique of “strip milling” is used where full-depth removal, up to 12 inches, is desired.

Traditional Pattern, with grooves spaced 5/8th of an inch apart, is the industry standard for asphalt overlay. Suitable for milling up to 8 inches in depth, it allows production with an acceptable temporary driving surface.

Profiling Pattern, described as a fine-textured version of the traditional pattern, requires more teeth on the drum for reduced spacing of 3/8th of an inch. Best used on cuts no deeper than 2 inches, the result is a surface suitable for driving, with or without fresh asphalt overlay.

And Micro-Milling, sometimes referred to as “carbide grinding,” is performed prior to a seal coat to re-establish profile, grade and skid-resistance or to “de-slick” flushed pavements. The typical pattern of 1/5th of an inch is best used on thin cuts of no more than an inch deep.

A smooth milled surface with the correct profile provides two major benefits for paving contractors, Caterpillar Paving Products reported in a recent New Hampshire and Vermont case study: the crew would be able to pave both lifts using grade control on both sides of the paver, thus avoiding smoothness-losing profile built with slope control; and total smoothness improvement would not confined to just the leveling and wear courses.

“Milling contractors are entering an era now where the word ‘milling’ needs to be thought more of as ‘profiling,’” says West, Terex Roadbuilding product support specialist. “Regardless, you have to have weight, horsepower and grade control in order to maintain a productive balance. You just can’t take an undersized machine, place it on an oversized task, and expect a happy result.”

Half or Full

So, does this mean bigger is better? That depends on where you’re working, says West.

“Some jurisdictions, if you’re going to do mill-and-fill, will not accept half-lane cuts. You either cut the entire lane or you’re not going to not get the project.” This, he says, is often an agency’s reaction to past problems with contractors not being able to maintain cross-slope. One match between two lanes is easier to hold than mid-lane breaks.

Having said that, “there’s still merit” for a half-lane machine working on roadways squeezed between the need for rehab and the demand to keep traffic flowing, says West. “The motoring public does not have a problem with us giving them a smooth, new surface to drive on. They just don’t want you to get in their way while you do it,” he says. “If we ever find that magic formula to do both at once, we’re all going to be very rich and famous people.

“They’re asking us to do more work in less time in less space, basically.

An answer, among advice offered by roadbuilding equipment manufacturer Wirtgen America, lies in the contractor’s use of manpower. “It’s important that an owner keep his crew with a machine as long as he can,” recommends Jeff Wiley, senior vice president. “It’s not a good idea to send the crew back to the union hall at the end of the year, and get a new operator and crew the next year that has to be trained all over again on that machine. When crews stay on a machine month after month, year after year, they understand it; they know what to do on the machine to keep it up and running.

“The best crews are those that have been with the machine for the life of the machine.”

This approach works particularly well today, when cash-tightened agencies are increasingly looking to “near-term remedies” such as mill-and-fill, says West, closing in on 30 years with Terex Roadbuilding and its predecessor companies. “Our Rotomill did for the milling industry in the 1970s what our RS500 did for the reclamation/stabilization world in the late ‘80s,” he says. “It revolutionized it into a full-blown subcontractor-oriented marketplace.”

Say What? Smooth Operators

“The highway system that we have in place today is second to none. In fact, over the last two decades, I’ve watched industry have to incorporate rumble strips – which we did not use to do routinely – because we’re falling asleep at the wheel because the roads are so smooth. We’re putting rumble strips by mandate out there to wake you back up.”

John West

Product Support Specialist

Terex Roadbuilding

The 5

Echoing the words of its fellow milling machine manufacturers, Atlas Copco’s Dynapac offers tips to contractors to get the most out of their planers. According to Tom Chastain, product manager, pavers/planers:

Doing a visual walk-around allows a person to see areas of concern, such as loose or damaged tracks, worn or torn belts, and hydraulic leaks.

Proper daily drum maintenance should be done either before or at the end of the machine’s working shift. Specific attention should be paid for inspection and replacement of milling teeth and holders. Depending on the cutting system, holders may need to be tightened down according to the manufacturer’s specifications.

Washing of the machine is vital. This not only allows the machine to run more smoothly, but this can also prevent premature wear. A clean machine also allows potential issues to be more visible while doing the walk-around inspection.

Daily lubricating of all necessary components prolongs the life of the components and prevents premature failures. Use manufacturer-recommended lubricants, or at least lubricants that have been approved by the manufacturer and/or vendor.

Understanding and communication amongst the crew is critical. The most vital part of a milling operation is a quality crew. If the crew understands the job requirements and has done the proper maintenance on the milling machine itself, the program should go according to plan . . .

Well, adds Chastain, as much as it can, that is: Job scenarios do change seemingly every minute.

Handling the stormwater/erosion dynamic

By Tina Grady Barbaccia

Sediment. That’s the problem.

The City of Longview, Wash. tests permeability on Ohio Street.

Barry Fagan, Alabama Department of Transportation (ALDOT) environmental program engineer and a certified professional in erosion and sediment control, says that the “construction industry spends millions of dollars each year on construction stormwater management, yet sediment is among the top impairments of our nation’s waters with the construction industry being blamed for a good portion of it.”

Fagan says that BMP, the acronym for Best Management Practice, is often more likely to signify Best Manufactured Product because the desire for a quick, easy fix is replacing “actual thinking and application management.” In reality, a BMP is a physical, chemical, structural or managerial practice that prevents, reduces or treats contamination of water or that prevents or reduces soil erosion.

What’s more, he says, the amount of money spent on erosion control is not a reliable indicator of success. “Sediment control alone is ineffective,” points out Fagan. Other management tools and resources must be called into the fight, before the problem arises and after it has.

Having said that, Fagan points out that existing natural vegetation is the most effective BMP available. “It also happens to be one of the most economical,” he says.

In the Portland, Ore., erosion-control BMPs are required during all ground-disturbing activity until permanent site ground covers are in place. “Stormwater control is a vital element to prevent erosion,” according to Portland’s Bureau of Development Services. Stormwater control practices — including methods to convey, divert, treat and control stormwater flow rates and volumes — can be complex. Runoff volumes and rates also can be hard to predict.

Also, increasingly-tighter stormwater restrictions have made implementation of BMPs increasingly important. From an engineering perspective, it’s absolutely critical, explains John Kurdziel, P.E., director of technical services and market development for drainage pipe company ADS/Hancor Inc. When it comes to the removal of sediment from stormwater, there are several products available that are designed to handle sediments, he says.

And when it comes to sediment, there’s more than one way to attack it. “By diverting and conveying flowing water around, under and over a work area, the amount of sediment-carrying water that must be managed is reduced,” explains Fagan. “Water velocity also affects erosion and sediment control efforts. By increasing the velocity of water, its erosive energy, the mass of soil being transported and the size of the particle being carried are also increased.”

Removing chemicals and oil from the water is also vitally important and must also be considered a best practice, says Kurdziel. “Chemicals and oils can have a much bigger impact than just the sands and the sediment that gets pushed through the systems,” he says. “The intent is that the material coming through the unit will outlet to a stream or a natural waterway with the same type quality of rainwater that initially hit the ground. You need to mitigate it before it becomes a problem because you don’t want to have any chemicals or particulates going downstream that would not normally be there.”

Regulations are becoming more intense when it comes to water quality from construction sites. Scott Erickson, principal of Evolution Paving Resources and president of Salem, Ore.-based Quality Concrete, says “stormwater is a freight train coming your way. How you deal with it will depend on how much of the market you get.” By 2014, “the noose is going to be even tighter around pavement designers’ and developers’ necks,” Erickson points out.

Pervious Pavement

The Georgia Department of Natural Resources has projected a 300- to 500-percent growth in pervious concrete in the next five years, Dale Fisher, executive director of the National Pervious Concrete Pavement Association, said during a press conference at CONEXPO-CON/AGG 2011 in Las Vegas. The agency is using pervious pavement for its Amicalola River Streamside Project in Georgia.

Low-impact pervious pavement allows water to pass directly through, which reduces the runoff from a site and allows stormwater to be cleaner and cooler. There have been recent advances in pervious pavement to further enhance its benefits. A pervious concrete infiltration fabric, PERC, has been recently introduced to the market. It’s made from recycled PET from soda bottles and has small pores to restrict dirt and particulates, which can contribute to clogging storm drains. Fisher says this type of technology will enhance performance for pervious concrete systems in paving installations. This type of fabric is engineered to maintain separation between the base and sub-base, which provides structural support to the pavement but allows stormwater to infiltrate freely into underlying soils, he says. “When used on an impermeable subbase, it mimics the microbial activity found in soils and contributes to improved water quality.”

The use of pervious pavements is creating dramatic paradigm changes for pavement designers. For years, pavement has been built like a bathtub — water runs onto the pavement and into a catch basin. Sidewalks, grass and everything else that’s associated with it was sloped so water would run into the pavement and then sheet flow to the low point of the basin. “There it disappears into a pipe or a swale and is out of everyone’s hair,” Erickson says.

The use of pervious pavement technology has been instrumental in keeping water onsite when it’s an appropriate stormwater solution for the application. “While the goal is to maintain as much water onsite as possible, we now want water that falls on landscaping to stay on landscaping instead of flowing onto the pavement,” Erickson says. “If we use curbs, we notch them so any overflow runs onto the landscaping.”

Pervious pavement can be used to harness problematic stormwater to help control erosion.

The City of Austin, Texas, is harnessing its problematic stormwater with pervious pavement to help control erosion through its Pease Park district. The city is building about 15 miles of trails through a section of the park to help corral the stormwater and prevent the trails eroding into the creek. “In general, the weather there is constant drought interrupted by occasional major floods,” says Erickson. “The city couldn’t even keep gravel on a trail next to a creek that goes by the park, so it decided to put in some pervious concrete trails.”

For the Five Pillars of Construction Stormwater Management and Three Tips on Designing a Retention/Detention System, go to the Better Roads digital edition at betterroads.com and click on “Experience our Full Digital Edition.”

Cow Roads

Building new roads can overcome a number of mud and erosion problems. That’s exactly how one dairy farmer – Misty Meadow Dairy – in Tillamook, Ore., dealt with a constantly flooded fields. Tillamook is on the Oregon Coast, where there are multiple canyons, says Scott Erickson, principal of Evolution Paving Resources and president of Salem, Ore.-based Quality Concrete. At times, these canyons get up to 4 inches of rain in a short time, and flooding follows. “One farmer got so tired of maintaining his cow pastures that he put in 2.6 miles of concrete trails that were 11 feet wide so the cows could march in on it,” says Erickson, who was on the team that helped install the trails. “The farmer says it saved him more than $50,000 a year by not having to pay for someone to come in and fix the cattle’s feet with all the mud and rocks.” (For a video of pervious pavement being installed at the dairy farm, go to evolutionpaving.com/proudcts/slipform-pavers.htm.)

Mobile Barrier Trailer helps keep workers safe and traffic flowing

By Tina Grady Barbaccia

The North Texas Tollway Authority (NTTA) has found a way of minimizing traffic disruption and maximizing worker safety in short-duration, rapid-work zones, says J.C. Wood, NTTA’s director of maintenance.

The solution is an integrated, rigid-wall trailer pulled into place by a standard semi-tractor.

Looking much like an 18-wheeler’s flatbed trailer, it is hooked to a semi-tractor and can be driven down the road and parked in place to operate as a rigid, strong, one-piece work zone barrier, functioning in much the same way as a concrete barrier, says Wood.

Branded as MBT-1 (Mobile Barrier Trailer), the barrier is made by Golden, Colo.-based Mobile Barriers. It has been crash-tested and accepted by the Federal Highway Administration (FHWA) for use on the National Highway System under both NCHRP350 and the new MASH Standards at both TL-2 and TL-3 levels. The barriers configure from 42 feet to more than 100 feet, and can be set up to protect to the right or left side of the road. NTTA’s mobile barrier trailers use onboard generators and onboard lights for night work.

Typically, when work zones are created, a truck delivers barrels and cones, hand-placed to set the boundaries of the worksite. But barrels and cones are no match for an errant driver.

The Mobile Barrier Trailer configures from 42 feet to more than 100 feet in length.

The mobile barrier is essentially a steel beam that walls off the work area. The barrier delivers NTTA another advantage. It can be set up, and later removed, quickly, helping to minimize traffic disruption. “The overall time that you are in the road is reduced,” Wood points out. “It speeds up the process.”

Wood says one of the best testaments to the barrier’s effectiveness is how willing NTTA’s employees are to use it. “They don’t want to go in and work on the road without this piece of equipment,” he adds. “It’s a very scary thing to be out in the work zone if the only thing separating you between motorists going 70 miles per hour and the work zone is a cone or barrel.

“If any activity is going to occur in the roadway itself or on the shoulder, protection is needed,” says Wood. “All of our facilities have high-traffic volume. We have about 80,000 cars per day. All of our facilities are six-lane with very, very high-speed traffic. It’s an urban area so right-of-way is pretty constrained, making it a hazardous place to work. We want to make it safe for the employees — we have a goal of ‘no boots on the pavements’ unless they are behind positive protection.”

The barriers also have a positive effect on safety through their appearance, and can help speed up work because workers are less worried by passing traffic. They are bright orange, and often referred to by NTTA employees as ‘big orange pumpkins’,” says Mark Bloschock, a retired Texas DOT employee who is now vice president of Plano, Texas-based VRX, a consulting firm that is currently working with NTTA. “The first priority in any work zone is safety — to protect against an errant vehicle,” explains Bloschock. “The second priority is to minimize traffic disruptions by creating a fast work zone or a very short duration work zone. The offshoot of all this is worker safety and productivity.”

Bloschock gives the example of how mobile barrier trailers can assist in minimal traffic disruption with a crash cushion repair. Typically, a “ring of steel” would need to be established. The substitute is a mobile barrier trailer and one or two vehicles. Not only does it keep workers safe, but “they can immediately start working on the crash cushion,” he says.

The project begins at about 5 a.m. with the set-up of warning signs, arrowboards and barrels. The entire project, including traffic control set-up, the repair of the crash cushion and the taking down of all the traffic control is finished by 6:15 a.m. or sooner. Because of the protection afforded by the MBT, the project is safely accomplished with fewer dump trucks necessary to block access to the workers and fewer workers needed to drive or remain in the trucks.

“It might have taken an hour and a half or an hour and 45 minutes to do what can be done in an hour and 15 minutes,” Bloschock says.

The sheer size of a mobile barrier such as the MBT-1 assists with limiting traffic disruption to get workers in and out. This barrier can be as little as 42 feet long or can be put into 20-foot sections to become as long as 102 feet, he says. Traffic flows by the barrier trailer better than through an unprotected work zone, notes Walt Black, a retired equipment manager with the Colorado Department of Transportation (CDOT), who now works as vice president of equipment for Mobile Barriers. CDOT used the mobile barriers during guardrail repair work on I-70 through Denver. “With the trailer on site, motorists can’t look into the work zone, so it cuts down on rubbernecking,” Black says. “Since [motorists] can’t see into the work zone, they just drive on.” This helped CDOT repair 42 sticks of guardrail on I-70 in the time it usually takes to do six to eight sticks of guardrail. “It took about seven hours to do 42 sticks,” Black says. “It normally would have taken 32 to 40 hours. It was completed it one night, where it typically would have taken a week.”

NTTA’s Wood adds that although this type of mobile barrier technology is “relatively new technology,” it’s just starting to come into the mainstream. “You will definitely start seeing more of it,” Wood says. “It just makes sense.” The NTTA has two mobile barriers and will soon have access to a third through a new eight-year contract with the Maryland-based contractor Roy Jorgenson to work on the George Bush Turnpike. “We required the contractor to purchase a mobile barrier,” Wood says. “We feel very strongly that the safety is well worth the expenditure. There will be lane closures for our IT department to work on the toll collection equipment in bucket trucks. Mobile barrier trailers will provide positive protection when our employees are out working. Everybody should be protecting their employees and providing positive protection for them.”

For an MBT-1 overview, go to mobilebarriers.com/specs.htm

Where the Rubber is the Road

Rubberized asphalt paves the way for happy taxpayers and road travelers . . . even four-legged ones

By Mike Anderson

Over the past 20 years, Gary Shaw spent considerable time educating people in his rural Ontario, Canada county and beyond about rubberized asphalt pavement. And for those people not part of the local elementary school classes or international conferences he spoke to, the former County of Grey transportation and public safety director had huge signs posted along portions of rubberized county roads that would ensure they understood clearly what they were traveling on.

Not that horses need to read.

Shaw recalls a sudden drop-in to his Owen Sound office a few years ago from a member of the intensely private, highly devout, completely respectful Mennonite community that farms alongside the most quiet of secondary roads, as about as far away, literally and figuratively, from even the quaint villages and small towns that dot the Ontario county. When Mennonite community members do need to go to town, it’s most often via horse-pulled buggies. “We really like those rubber roads,” Shaw was told by his surprise visitor. “So I asked him, ‘Why do you like them?’ And he said, ‘Well, our horses can tell when they go off conventional asphalt onto rubber, because their gait will increase.’”

If that isn’t the ultimate testament to highway productivity, then what is?

The County of Grey, with a closed-loop tire recycling process, turned its own increasing stockpiles of discarded tires into a new highway pavement program; a problem for one department of local government thus became a solution for another. Other jurisdictions throughout the continent secure the crumb rubber they incorporate into their asphalt from companies specializing in the recycling of tire rubber.

“Our whole purpose is to try to educate the engineer on how to make the road act more like a tire, really,” says Doug Carlson, vice president of asphalt products with Liberty Tire Recycling, which itself reclaims more than one-third of all discarded tires in the United States. Different types of asphalt mixes are used depending on climate, and overall the range for the paving material is about 80 degrees C; comparatively, says Carlson, tires have a range of about 150 degrees C and, most of the time, users don’t change them from condition to condition. “The big challenge with asphalt is that it gets too soft when it’s hot out and too brittle when it’s cold,” he says. “Well, the tire rubber now used in asphalt counteracts that weakness. Rubber in an asphalt binder will make it last longer under a wide range of temperatures and climatic conditions.”

No More Bouncing Checks

The use of crumb rubber in an asphalt mix goes back 40 years, particularly in the U.S. Southwest, but the technology is growing in application throughout the world, says Carlson.

“The biggest factor for that is the realization that tire rubber can be used as a substitute to virgin polymers commonly used in asphalt. The switch from a virgin polymer to a tire rubber component is a driving factor for increased usage, and of course that is related to the cost of crude oil. As crude oil has increased, the cost of polymers has increased,” he says. “Cost savings is the biggest issue in today’s market, with high asphalt prices and high polymer prices. Tire rubber’s been steady in price – very stable over the past 15 years.

“If state agencies are not using it routinely, at least they are developing a specification that they can use if there might be a shortage of polymers – if polymers become scarce or just too expensive.”

States once leery of noise-reducing rubberized asphalt in open graded friction courses, due to negative experiences with failing binders in the ‘80s, are increasingly coming on board with the benefits of the elasticized asphalt in such applications, he’s observed. “Many are taking a second look, maybe even a third look, at these mixes,” says Carlson, whose company is based in Pittsburgh, “particularly in the Northeast, where you have a lot of benefits for the splash and spray reduction.” He notes: New Jersey has started used rubber in its open graded friction courses; Massachusetts is using rubber in a surface wearing course as part of its routine short-line pavement rehab program.

On the whole, says Carlson, “where they’re substituting tire rubber for polymers, the contractors are saving the state’s DOT anywhere from $2 to $5 per ton of mix. It adds up. On big projects, you can save anywhere from $50,000 to $250,000 rather quickly.”

This could result in a fund-strapped agency, local or state, being able to complete one additional project per year than otherwise possible.

Back in rural Ontario, where healthy skepticism and vocal opinions on most issues have never gone out of vogue, today there’s more than just the universal desire for more roadwork, but an actual enthusiasm for what that additional paving job should entail.

“The public believes in this program now so much,” says Shaw, “that they’ll actually phone in and say, ‘We hear you’re going to pave our road this year . . . we just want to make sure it’s going to be a rubberized asphalt road.’

‘Re-Made in America’

a Statement of Liberty

From two locations in 2000, Liberty Tire Recycling now operates 33 facilities across North America capable of producing more than 250 million tons of crumb rubber for uses ranging from welcome mats and weightlifting plates to railroad ties and highway asphalt.

What began 11 years ago as a scrap tire collection service to solve a solid-waste problem remains the starting point in a process, says Doug Carlson, vice president of asphalt products for the Pittsburgh-based company.

Liberty has contracts to collect scrap tires from leading big-box tire retailers. The tires are taken to a Liberty facility, where they are run through shredding machines, removing the steel via magnets and the fiber and fluff via vacuum or air-blown systems. “You end up with a pure scrap tire rubber particle that’s about the size of ground coffee,” says Carlson, “and that is packaged and shipped to the contractors, where they can add it to an asphalt product for a mix in accordance with the state’s specs.”

The crumb rubber is shipped in a bulk bag, or “a super sack” as Liberty calls it: “It will vary in weight depending on the size of the rubber that’s in it, anywhere from 1,800 pounds to 2,200 pounds, but generally it’s about a ton.”

What does that translate to on the road? “It depends on the type of mix,” says Carlson. “The rubber content in an asphalt mix can vary from 10 pounds per ton all the way up to 30 pounds per ton of mix, so one super sack can go a long way in production of hot mix.” At one to three tires per ton of hot mix, “that translates anywhere from 800 to 2,000 tires per lane-mile of roadway.”

Company Makes A Flexible Argument

Calling it “The Road to Sustainability,” Liberty Tire Recycling pitches rubberized asphalt by educating on its benefits:

Cracking and rutting resistance: Superior elasticity reduces the occurrence of cracking caused by vertical or horizontal movements beneath the overlay as a result of traffic loads, temperature fluctuations and shifting earth.

Skid resistance: In wet conditions, decreased splash and spray combine with better traction for a safer traveling environment.

Maintenance cost reduction: While in most cases using the same equipment as traditional asphalt application on roadways, longer-lasting properties reduce long-term maintenance costs.

Noise reduction: By upwards of 5 decibels, a quieter traveling surface meets the increasing requirements of public-complaint-conscious agencies.

Here’s A Clean Spec For You

Among the challenges encountered when Ontario’s rural County of Grey started laying rubberized hot-mix asphalt 20 years ago was the picking up of freshly-laid material by the compactors.

Then county transportation and public safety director, Gary Shaw, made an adjustment that today is written into every tender put out for county rubberized pavement work. It reads: Ivory liquid soap must be used with the water solution of the rollers in order to reduce the pickup of asphalt on the roller tires and drums.

No word whether Shaw, having just ended a 45-year career with the County of Grey, is the next Ivory Guy.

The Savvy and Science of Pickup Servicing

Service intervals are not ‘one size fits all’ routines

Today’s fleet and service managers have a lot of responsibility riding on their shoulders, as they balance productivity with costs of operation. Vehicles and equipment in the shop for repairs are expected, but they hurt the bottom line.

That’s why preventive maintenance is so critical to controlling operational costs. The big question, however, is how often should the pickups in your fleet be serviced? Do you follow the vehicle owner’s manual or set up your own system?

The answers are not cut and dry. What works for one company or agency may not be right for another.

For example, do you know which battery to connect to when you jump-start a 6.7L Power Stroke, what coolant is required for the Hybrid Silverado/Sierra’s control module, or which eight of the Ram 4.7’s 16 spark plugs are changed more frequently?

Vehicle owner’s manuals and supplements may not be the most exciting prose, but they do provide valuable service information – including definitions of “severe service” and listed maintenance schedules.

Most new pickup service intervals specify a limit between oil changes of 3,000 miles in severe service and up to 8,000 with easy use. The typical fleet pickup usually falls into the severe-service category.

But most also have built-in oil minders that use drivetrain sensors and determine the interval for you; a “change oil” message on the dash display pops up reminding the driver an oil/filter change should be completed within 500 miles.

Bear in mind these electronic minders don’t sample the oil. They monitor heat, oil level and a lot of other parameters to determine what percentage of oil life remains before letting you know it’s time for a service.

Also, they may not track engine run time, and a truck that sits idling for long periods of time may need fresh oil even if the minder doesn’t say so. Relying on the minder is a poor excuse for not pulling the dipstick while refueling.

Extending oil drain cycles beyond 8,000 miles, even with synthetics and oil sampling, isn’t a good idea, either. No one we consulted makes that recommendation for newer diesels (anything built after Jan. 1, 2007) because of the effects of emission control and changes to the required oil specification.

Synthetic oils may still be used to maximize the extreme lubrication protection in cold and heat, but running them longer jeopardizes the engine warranty.

Regular oil analysis is still the best way to determine when the oil and filters need to be changed in individual pickups. Consult with your oil analysis lab on how to set up a baseline for each vehicle, the analysis frequency and how to read the results.

Those results will tell you when the next oil service is needed, and keep you aware of wear issues that may be brewing inside the engine.

Periodic and recorded service is the simplest, most cost-effective way to keep your truck running reliably, maintain the warranty coverage and preserve resale value. And regular cleaning makes life easier on drivers and identifies problems earlier.

With no-maintenance electronics playing an ever-larger role in the operation of late-model pickups, most routine service boils down to lubricants, filters, brakes and tires.

A decent service log, backed up daily, is the easiest way to ensure your truck gets attention when needed. This can be as detailed as fleet maintenance software, a good relationship with your dealer’s service department, a laptop spreadsheet or notebook, and a file cabinet.

Date, odometer miles, work performed, receipts with part numbers and a notation on the calendar approximating the next time service is due is the minimum; your accountant or mechanic may recommend more. And if you’re forgetful or lazy, you need an effective reminder system.

Contamination kills

Engine oil doesn’t really wear out. The additive package added to the base oil stocks (detergents, anti-foaming agents, etc.) wears out, and contaminants get in the oil.

In newer diesels with diesel particulate filters (DPF) extra fuel is occasionally injected to “regenerate” the DPF and since it’s done after the combustion event, some fuel inevitably washes down the cylinder walls and dilutes the oil no matter what kind of oil it is. (The 2011 Duramax has a ninth injector in the exhaust system that helps alleviate this issue.)

That fuel dilution is a primary reason you can’t extend the change interval on new diesels: True, you could do frequent analysis for fuel dilution, but the time and money spent on the synthetics and analysis would buy a conventional oil change anyway, so you’re not saving anything.

Unless you’re improperly using the truck outside its design parameters – or in extreme climates – do a cost/benefit analysis before choosing a synthetic engine oil in any new pickup.

Also note that in the long run — this is why you document — pushing a service interval to the recommended oil change may not pay off overall.

One large fleet manager we spoke to in Los Angeles found the 6,000- or 7,500-mile intervals in the book were fine for engine oil. But those miles were too far for the physical inspection that accompanies routine service, so any savings in oil service were more than offset by brake and other repairs not caught sooner.

While manuals are thorough, service managers and pickup owners should never pass up a chance to ensure the cooling stack is clean and lug nuts torqued on all the wheels – including those on the trailer.

What to Use

Your manufacturer specifies fluids, and most oils have an American Petroleum Institute identifier with the classification and viscosity (e.g., API CJ-4 5W-40).

Synthetic lubes are approved, although many experts we consulted advised such lubes should not be used (unless factory-filled) for the first 5,000-10,000 miles to ensure proper piston ring seating.

Synthetic lubricants are especially beneficial in severe climates. For example, the 2011 Ram diesel manual dictates 5W-40 synthetic oil for operation at zero degrees F or lower.

Note also that fluid ratings are not always “backward-compatible.” In other words, newer is not always better despite petroleum industry assurances. A manual gearbox that calls for GL-4 will not last longer on GL-5; in fact, some parts will wear quicker.

All brake fluids comply with Federal standards but DOT 3, DOT 4 and DOT 5 are not newer and better (5 is silicone-based, 5.1 is not). Engine oils are API-classed S for gasoline engines and C for diesel.

The newest diesel oil standard is CJ-4. Some long-term diesel owners have found the CJ-4 for ULSD/DPF engines doesn’t have the same levels of zinc, phosphorous and detergents, and is not as good as the CI-4 Plus that preceded it. Many oil companies don’t want to produce two oils, but if you can find it, CI-4 Plus is often regarded as better for pre-DPF-era diesels.

If your truck requires any additives, like those for limited-slip differentials coolants in earlier Power Strokes or some fuel stabilizing agents, the owner’s manual will says so. Otherwise, forget additives and put that money to better use doing routine service.

About filters

Almost every lubricated component has some sort of filtering device, from a magnetic drain plug to fuel filters. These are cheap insurance when the proper parts are changed at recommended intervals or during an associated repair.

In those cases where truck and engine come from different manufacturers (e.g., Cummins/Dodge, International/Ford) an engine company’s service provider may have better prices and parts availability.

“Proper” part refers to that named acceptable by the manufacturer (engine or truck); more than one diesel pickup owner has suffered an engine failure because the media from an aftermarket oil filter broke off and plugged a piston cooling jet, and warranty coverage was denied.

If a factory filter is $15, a cheap one $8, and an engine $10,000, which is the best value?

Two other parameters deserve careful consideration: clutch-pack limited-slip differentials and diesel fuel filters.

Fuel filters on newer diesel engines are critical. With pressures more than 20,000 psi, even the smallest contaminant can do damage (think what your pressure washer does at one-tenth that pressure), and parts are not cheap.

The thousandths-of-an-inch clearance in a crank bearing is huge compared to the tolerance in diesel injection, where writing on a part with a Sharpie means it won’t fit anymore. If you’re a do-it-yourselfer, don’t pre-fill a diesel fuel filter because your eye can’t see contaminants that could cause damage.

Limited-slips improve traction and are an inexpensive factory option considering the traction advantage over an open-diff. Nearly all of them require periodic service and an additive to work correctly. Forget the additive and they eventually become unlimited-slips.

This article was written by G.R. Whale, a contributor to our sister publication ProPickup magazine

Diesel alternatives making headway in the work truck world.

By Jack Roberts

Several years ago, the National Truck Equipment Association (NTEA) Work Truck Show aligned itself with the newly born Green Truck movement. This partnership, that seemed so unlikely at first, has proven to be highly prescient given the alarming spikes in gasoline and diesel prices experienced in 2007-2008. Over the years, the Work Truck Show has evolved as a showcase for the latest in alternative fuel vehicle technology. And this year, with fuel prices once again climbing skyward at an alarmingly fast rate, the show’s emphasis was clearly on low cost of vehicle ownership throughout the lifecycle of a work truck.

The stars of the show in Indianapolis last month were natural gas-powered vehicles – a market segment that is maturing rapidly, particularly in terms of infrastructure (i.e., refueling) issues and an ever-widening array of product offerings for every imaginable vehicle application. Virtually every OEM at the show proudly displayed new propane (LPG) or compressed natural gas (CNG) vehicles in their booths. A wide array of new hybrid-drive trucks as well as all-electric trucks also took their turn in the spotlight.

But it appears at this early juncture that LPG and CNG drivetrains are quickly taking the lead as the alternative fuel of choice as the costs of diesel and gasoline approach the $4-a-gallon mark. At a Green Truck Ride-n-Drive for editors during the show, I was able to take several LPG and CNG vehicles out on the road to see just how well they performed. The results are surprising. These spark-ignited, clean alt-fuel burning engines are typically as quiet as gasoline engines. Indeed, in most cases, a driver behind the wheel would not be able to tell much of a difference between a natural gas engine and a gasoline one. And while it is true that natural gas does not possess the power density of diesel or gasoline, the difference from behind the steering wheel is actually negligible: I found throttle response to be noticeably peppy during my test drives. Unless you encourage your drivers to drag-race your trucks, I simply don’t think this power density difference (roughly a 10-percent depreciation compared to gasoline engines) is a major inhibitor to adopting this technology. A similar reduction in overall vehicle range when using natural gas engines would be an obvious disadvantage in long-haul applications. But the fall-off is relatively minor and would not pose any major problems for construction trucks working in a specific geographic area and returning to a set location every evening.

And the best news is that the United States currently has one of the largest supplies of natural gas reserves in the world. Even better news is the fact that, as of this writing, propane and natural gas is currently selling for around $2.15 a gallon.

There is no doubt that diesel will continue to be the fuel of choice in construction trucking applications for the foreseeable future. But as fuel prices rise, fleet managers will be happy to know there are increasingly viable alternatives to gasoline and diesel on the market now that can help alleviate skyrocketing operating cost.

Western Star’s Newest Star

Western Star Truck Sales used the show to introduce an all-new Class 8 vocational truck, the 4700. The company says with a 110-inch BBC (bumper to back cab) length, and available in a set-forward or setback configuration, the truck is the “ideal solution to meet the needs of the dump, mixer, crane, roll-off, sewer vac and plow segments” of the industry. Powertrain options include the Detroit Diesel DD13 and the Cummins ISC and ISL engine. A broad range of transmissions is also available, including the latest Eaton Ultrashift PLUS and the Allison 3000 and 4000 series.

The truck features a galvannealed steel cab, a newly-designed sloping hood for better visibility, and a 55-degree wheelcut for better maneuverability. The truck’s body-builder interface connectors and transmission control unit is located in-cab. There is also a bolt-in pass-through plate in the cab floor that eliminates unnecessary drilling and an easily accessible routing path for wiring.

In-cab batteries free 17 to 34 inches of rail space for body equipment installation, and the 4700’s DEF and air tanks can be placed under the cab to free additional rail space. Air and electrical lines are suspended away from the frame rails to reduce rubbing and to allow road debris to pass behind them rather than build up in the bundle.

Hino Hybrids

The new Hino 155h and 195h Diesel-Electric Hybrid cab-over-engine trucks were designed from the ground up for the North American market, says the company.

The Class 4 and Class 5 diesel models will be available starting in August of 2011 at Hino Trucks dealerships. The hybrid models will follow a “roll out” approach and will be available in the following markets in December of 2011: New York; Philadelphia; Washington, D.C.; Chicago; Atlanta; Dallas; Houston and California.

Isuzu’s New N-Series

Isuzu introduced its 2012 N-Series trucks at the show. The 5.2-liter turbo diesel found in every 2012 NPR-HD, NQR and NRR generates more horsepower and lower emissions while delivering better fuel economy than earlier-generation engines, says the company.

All 2012 Isuzu N-Series trucks meet EPA 2010 and CARB OBD emissions standards, and are clean-idle-certified. Isuzu diesel trucks are the first in their class to offer Selective Catalytic Reduction (SCR) to reduce NOx emissions by 85 percent.

The N-Series trucks have a tighter turning circle than earlier models. Aisin six-speed automatic transmissions are standard on every 2012 diesel N-Series truck.

The 2012 N-Series gas truck is powered by General Motors’ 6.0L Gen IV small block V-8 engine, coupled to a new double-overdrive, six-speed automatic transmission with lockup torque converter that improves both vehicle performance and fuel economy. The engine boasts 297 horsepower and 372 foot-pounds of torque, a 100,000-mile maintenance-free ignition system, a long-life timing chain and cast stainless-steel exhaust manifolds.

New for 2012, the company’s N-Series gas truck is also available with an optional CNG/LPG-capable engine.

Hella Lights It Up

Hella launched the Hella Mega Beam LED Work Lamp Generation II at the show. This compact, high-output work lamp uses four high-performance LEDs as the light source and delivers 600 lumens of light output with a minimal power consumption of 15 watts. The low-power consumption requirement of Mega Beam’s LEDs makes it ideally suited for use on battery-operated vehicles or vehicles where the alternator is under heavy load.

At a temperature of 6,500 degrees K, the Mega Beam creates a bright white light that provides exceptional close-range illumination similar to daylight, says the company. This means, says Hella, that colors can be distinguished more clearly in the dark than in the yellowish light of halogen bulbs, making perception to the human eye significantly easier, and preventing fatigue.

Hella has released its new Hella Power Beam 2000 LED Work Lamp that provides 2,200 lumens of lighting output (at a light color of 5,700 degrees K) while using only 43 watts of power. This lamp incorporates 16 high-performance, long-lasting LEDs. The company says the Hella Power Beam 2000 has a lifespan of more than 16,000 hours and will last 100 times longer than a traditional halogen bulb.

Fuso’s Canter Arrives

Mitsubishi Fuso Truck of America introduced its Canter FE/FG Series at the NTEA show. The new Class 3, 4 and 5 cabover models feature an advanced 4P10 turbocharged, dual-overhead cam, dual balance shaft, intercooled 4-cylinder diesel engine and a DUONIC six-speed, dual-clutch automated manual transmission.

Other features include Daimler’s BlueTec SCR emission control technology, extended service intervals (18,000 miles) and the company’s five-year/175,000-mile powertrain limited warranty.

The FE models feature dual-caliper hydraulic disc service brakes with vacuum servo assist and ABS on all four wheels. The FG 4×4 uses hydraulic drum service brakes with ABS all around. All models include an electronic brake override system.

Canter FE models with a 110.2-inch wheelbase feature a 34.1-foot turning circle, which the company says is “shorter than the turning diameter of a MINI Cooper (35.1 feet).”

TerraStar Goes Four Wheeling

Navistar unveiled the International TerraStar 4×4 commercial truck at the show. A 4×2 model was launched last year.

The new truck features a 300-horsepower, 6.4-liter MaxxForce 7 V-8 engine, delivering 660 foot-pounds of torque. This engine features a compacted graphite iron (CGI) block that offers high strength without added weight. The TerraStar features MaxxForce Advanced EGR emissions technology.

The TerraStar features what Navistar says is best-in-class visibility. With an industry-best 107-inch BBC, it offers outstanding maneuverability. There is room for three adults to fit comfortably in the front seat. The TerraStar is also available with optional extended cab or crew cab configurations.

Sometimes yes. Sometimes no.

By John Latta and John Baxter

Synthetic oils: They cost more, right? Well, yes, if you define “cost” as an upfront outlay. But a lifecycle cost analysis, or even a time-specific analysis – winter, for example – might convince you that under the appropriate circumstances, they more than pay for themselves.

Synthetic oil base stocks enable refiners to create engine oils with “better thermal stability,” says Maria Burcham, a technical advisor with ExxonMobil. Thermal stability is critical in keeping oil viscosity high enough for proper component protection.

At the extreme cold or extreme hot ends of the workday temperature scale, synthetics are out-performing mineral oils by losing less of their midrange structure.

“Synthetics offer both superior low-temperature performance and a high level of film strength at high temperatures to better protect all moving parts,” says Dan Arcy, a technical manager at Shell Lubricants. The fluid will be thin enough to flow easily and quickly, and reach all parts when you start up on a cold morning, yet it will remain more than thick enough when running at high speeds on a hot day.

While they are every bit as thick or “viscous” at normal operating temperatures as mineral lube, synthetics will start out thinner when you fire up equipment on a cold morning, says Baxter.

Almost all the oil ends up in the crankcase when the engine sits overnight. When the weather is cold, and at its coldest in the morning when you start work, synthetic oil pumps more quickly and circulates more freely. Also, wear surfaces will be lubricated more quickly with a lower-viscosity oil, and wear will be reduced

“We have a very cold winter now so, for example, there could be benefits to having city trucks with plows run synthetics,” says Arcy. “You get low-temperature pumpability and performance, and also ease and startability. Think what happens if several plows were delayed because they had starting problems, because oil was too thick and it was too cold. That’s costly to the community a number of ways.”

And there are incidental cold-weather costs.

“Cranking a cold engine puts more of a toll on the battery and starter, so there is some advantage there in using an easier-starting synthetic,” says Arcy. “We’ve done testing in cold temps to show how much battery power was needed to start an engine, and it’s significantly less with synthetics.”

The Contamination Problem

In environments where there is a ton of dust getting into the lube, synthetics sometimes lose their edge and may well need to be changed just as often as mineral lubes. It’s the contamination that ruins them and not breakdown. Here we go back to balancing cost and performance.

Any contamination is a threat, and working in a contaminated environment is one circumstance where the use of mineral lubes in drivetrain components might be preferred. In such cases, inspect the lube daily and replace it as frequently as it gets dirty or diluted with a less-expensive mineral oil, says Shell’s Arcy.

“In 2008, Hurricane Ike did some serious damage in Galveston [Texas] and tore up beaches,” recalls Arcy. “They started to rebuild beaches, so they were trucking sand around, working on the shore with dumps that sometimes drove into seawater, with axles going under the water. In a case like that, if I were asked to recommend oils, I wouldn’t have recommended synthetics because that oil would be contaminated, and it doesn’t make sense to use them when they have to be changed constantly in a work environment.”

Research clearly shows that synthetics are ideally suited for use in transmissions and axles, where combustion byproducts are not part of the equation.

Arcy also notes the critical difference between transmission and axle lubes, and the importance of using the right one. Transmission gear teeth are generally flat and the gears sit directly across from one another. In a drive axle, the large running gear sits at the level of the wheel bearings, but the pinion gear that drives it is off-center and at 90 degrees. The gear teeth in the drive axle rub together much more. Your dealer can help your selection for these two distinct uses.

The Semi-Synthetics Situation

There are also semi-synthetics on the market. As the name suggests, they are products that fall categorically somewhere between a mineral oil and a full synthetic. Now, they are also subject to a new debate.

Chevron Lubricants says it recently conducted benchmark and field testing to determine how its premium conventional heavy-duty motor oil, Delo 400 LE SAE 15W-40, performed against other major oil companies’ semi-synthetics. Test results show, the company says, that Delo 400 LE with ISOSYN Technology was equal to, if not better than, leading semi-synthetics in industry-recognized tests in the areas of wear control, oxidation and deposit control.

“Most heavy-duty semi-synthetics are touted as having superior performance over conventional oils, but that’s largely a marketing effort to persuade customers that the addition of synthetic base oil to an engine oil formulation will deliver a higher level of protection to critical components, thus justifying the extra price,” says Len Badal, commercial sector manager, Chevron Lubricants. “The notion that a semi-synthetic or synthetic blend provides significant benefits over a product like our Delo 400 LE 15W-40 is a myth.” Based on the research and general information provided by several large heavy-duty OEMs, says Badal, the performance benefits of semi-synthetics versus premium formulated heavy-duty engine oils are marginal at best, and typically don’t justify the additional price a customer must pay for them.

Through bench testing, Chevron documented examples of the competitive semi-synthetic performance myths in multiple areas versus its premium formulated Delo 400 LE 15W-40. In these tests, the Delo 400 LE with ISOSYN Technology performed equal to or better than many leading semi-synthetics. In one test designed to look at soot-related wear protection, Delo 400 LE significantly outperformed three of the four semi-synthetics tested, showing between 16- and 41-percent better wear protection in this test. Tests for oxidation and deposit control also showed very good performance results of Delo 400 LE versus the four major oil companies’ semi-synthetic products.

The company also conducted extended drain field tests on a dozen 15-liter Detroit Diesel DD15 engines. In these tests, Chevron claims to have extended drains out to 70,000 miles without filter changes, achieving the long drain intervals normally touted as a benefit of semi-synthetic products. According to the company, one engine was torn down and inspected at 400,000 miles and showed excellent durability and low wear.

Fuel Economy, Too

While fuel economy is not the key metric in transportation construction that it is in long-haul trucks, evidence from the trucking industry suggests synthetics could help construction fleet trucks that run up miles.

Peter Thomson, director of commercial and industrial marketing at Valvoline, notes that, “in addition to oxidative stability and low/high temperature performance, Valvoline has statistically-significant tests conducted by a leading independent laboratory that found fuel economy benefits for on-highway Class 8 trucks – up to three-percent maximum improvement in fuel economy using SAE J1321/TMC RMP 1103, Type II techniques.” Valvoline, says Thomson, “guarantees a minimum of 1.6-percent fuel saving, compared to traditional lubricants, when using our SmartWay accredited synthetic engine and axle oils, Premium Blue Extreme and Syn Gard FE in on-highway applications.”

Shell’s Arcy agrees that on-highway mpg advantages are proven, but there is no data to quantify off-highway miles per gallon advantages of synthetics. “I would anticipate that there’s a benefit there, but I don’t have the data. You see it on-highway, so why wouldn’t you see it off highway?”

Can You Swap Out?

It’s a commonly-asked question: Can you switch from mineral to synthetic? Shell’s Dan Arcy says it’s also one of the great myths that goes back and forth. For example, some customers use mineral oil in summer months and go into the synthetics for the winter months. “You can go back and forth without any issues. It’s a myth. Years ago, there used to be some issues, but now with seal compatibility there is no issue.”

What Are We Talking About?

So, what exactly are synthetics oils?

Valvoline executives point out that there are three categories of base oils that can be given the term:

Group III, which is highly-refined, hydroprocessed mineral oil,

Group IV, Polyalphaolefins or PAO, which is an engineered hydrocarbon-based product derived from natural gas, and

Group V, which are Esters, considered more applicable in industrial lubricants.

All offer chemically-stable and chemically-consistent base oils with high levels of oxidative resistance.