Repaving the pieces

March 12, 2007

Hurricanes are one of the most powerful forces of nature, and have brought widespread devastation to large areas of the U.S. The barrage of record-breaking storms hitting the Gulf States and eastern coastal regions in recent years have left in their wake billions of dollars in damages. Just mentioning the names Andrew, Opal and Katrina conjure images of torrential rains, flooding and severely devastated housing and infrastructure.

Hurricanes are one of the most powerful forces of nature, and have brought widespread devastation to large areas of the U.S. The barrage of record-breaking storms hitting the Gulf States and eastern coastal regions in recent years have left in their wake billions of dollars in damages. Just mentioning the names Andrew, Opal and Katrina conjure images of torrential rains, flooding and severely devastated housing and infrastructure.

Hurricane Ivan is another name deeply ingrained in the minds of residents in the Gulf of Mexico. It was the strongest hurricane of the 2004 season, reaching Category 5 status and hitting the U.S. as a Category 3 storm. The brunt of this hurricane hit Pensacola, Fla., home of asphalt paving contractor Panhandle Grading and Paving Inc.

Ivan was responsible for more than $10 billion in damages in the U.S., in which nearly half of its destruction was unleashed on the Pensacola area. "Ivan hit pretty hard and severely damaged the I-10 bridge over Escambia Bay," said Donald Long, vice president of Panhandle Grading and Paving Inc.

Founded by Johnnie Long, president, the family-owned Panhandle also is run by his two sons Jerry and Donald, and has been a staple in the Florida counties of Escambia, Santa Rosa and Okaloosa since 1979. The Longs are all too familiar with the fact that once a hurricane passes through a community, there is much rebuilding to be done, providing an abundance of opportunity for companies like Panhandle. But that demand is taxing.

"When you have infrastructure down, demand is immediate," said Donald Long. Ivan began to show the Long family some inefficiencies within its asphalt operations.

Nearly 12 years ago, Panhandle started a sister company, Group III, which produced asphalt for the company's paving operations and other local paving contractors. For years, the CMI PTD-300 portable asphalt plant's capacity and durability served the company well, producing approximately 200,000 tons of material annually.

However, Hurricane Ivan left behind a great deal of infrastructure damage. Panhandle was charged with rebuilding 10 miles of S.R. 399, which winds along the beaches between Escambia and Santa Rosa counties, affected by the storm.

"It was a major project that required 70,000 tons of mix within a three-month time frame," said Long. This was more than one-third Group III's average annual production within one quarter.

I-10, spanning Escambia Bay, also was severely damaged by Ivan. After the storm, it was more of a piecemeal bridge with temporary eastbound lanes, which resulted in traffic jams and long delays for crossing motorists.

Group III's single PTD-300 plant was located on the east side of the I-10 bridge in Santa Rosa County. The producer's trucks had to cross this bridge daily to deliver asphalt for reconstruction projects in Escambia County. "Just one minor accident on the bridge would cause a major back-up," said Long.

To keep pace with increasing asphalt demand, the producer demanded a lot of their middle-aged plant. The PTD-300 produced asphalt eight hours a day, year-round. Group III had run so much material through the plant that it was already on its second drum mixer.

High demand and tight production schedules left limited time for plant maintenance, which was relegated to mainly the weekends. Any minor plant problem occurring during the week would throw off the production schedule. According to Long, it was time for a second plant.

The timing for Group III's search for a second asphalt plant corresponded with ConExpo-Con/Agg in 2005, giving them the opportunity to visit several plant manufacturers in a single location. The final stop for producer representatives was the Terex outdoor booth, where they met with Steve O'Neal, district sales manager for Terex Roadbuilding. "We met with Johnnie and Donald to discuss what they were looking for," said O'Neal. "They had already done a lot of research, and they wanted a plant that would meet both current and future market demands."

Group III wanted to site the plant in Escambia County, on the east side of the hurricane-damaged I-10 bridge, giving them a plant on both sides of the bay. The plant had to be capable of running high percentages of RAP while staying within environmental compliance. The company also wanted a plant that would operate as dependably as the company's existing counterflow plant, so it could eventually expand total annual plant production to 300,000 tons per year.

After considering different plant designs, Group III representatives decided on the Terex E3-300 continuous counterflow drum-mix asphalt plant (Circle 900) from Terex Roadbuilding. The asphalt plant, in part, is based on the PTD-300 concept. However, it is the next evolution in the company's drum design, combining aspects of CMI and Cedarapids counterflow technologies into one plant. The drum uses three heat transfer zones--convective, radiant and conductive--to produce a wide variety of mix designs at capacities reaching 300 tons per hour.

The drum's outer RAP shell houses the secret to an exclusive RAP early entry feature. In this radiant heating zone, recycled asphalt is fully heated with a variable percentage of virgin aggregate prior to liquid asphalt injection in the conductive zone. "With the continuous counterflow mixing process, unburned hydrocarbons are drawn into the exhaust stream and incinerated," said O'Neal.

This allows producers to run high percentages of RAP without emitting blue smoke. "We run RAP in everything except for our surface mixes," said Long. "On average we run 20 to 22% of RAP in our designs, but we have used as much as 30 to 40% in certain mixes."

Group III equipped its new asphalt plant with three, 200-ton silos for mix storage. A five cold-feed bin aggregate system and two recycle material bins provide aggregate and RAP storage for a wide variety of mix designs. For environmental compliance, the producer chose an RA318P ROTO-AIRE baghouse and mineral filler silo.

Group III took delivery of the E3-300 plant shortly after the March 2005 trade show, and it was producing mix by mid-summer. The producer now has its second plant, located on the opposite side of Escambia Bay. The new plant, with its 600-ton total mix storage capacity, allows the producer to use less fuel. The plant operator can run all the mix designs for the day in a shorter period of time without excessive starting and stopping, which burns more fuel.

Adding the second plant allows for more time for scheduled maintenance at both plants. It also gives Group III production options that help keep Panhandle projects on schedule. If a problem occurs at one plant, the company can divert trucks to the other plant, so a project is not delayed.

Pavement compaction

Stone Construction Equipment Inc., Honeoye, N.Y., offers a full line of asphalt rollers: the Stone WolfPac Asphalt Rollers. Consisting of four separate rollers—the WolfPac 2500, 3100, 4100 and 6100—the WolfPac line is the most complete offering for confined area ride-on roller compaction to hit the pavement.

The WolfPac 2500 (Circle 901), the smallest of the line, is a 1¼-ton static roller ideal for smaller patching and paving jobs and landscape work. The WolfPac 2500 comes complete with everything customers demand as standard and is available with an 11-hp Honda engine. The WolPac 6100 (Circle 902) roller is the largest member of the line and is ideal for professional, high-volume compacting where productivity really counts. This double-drum drive, double-drum vibration machine offers more weight, faster travel speeds and a 47-in. footprint, and is available with a 35.5-hp water-cooled Kubota diesel engine.

Coal solutions

One of the largest concerns to the asphalt industry today is rising fuel costs. Coal is currently one of the least expensive fuels available. Astec Inc. of Chattanooga, Tenn., developed a coal burner, the new PhoenixCoal (Circle 903), to help hot-mix asphalt facilities take advantage of the lower cost of coal.

The efficient, low-maintenance PhoenixCoal provides substantial fuel cost savings by burning pulverized coal with oil or gas as a support fuel. The PhoenixCoal requires no refractory, performs at the same production rates as gas or oil units and is highly responsive to load changes.

Rolling stones

Multiquip’s new tandem and combination vibratory rollers are available in the 1.5- to 5-ton weight class, and emphasize maximum jobsite performance with high-frequency vibration, superior operator comfort, advanced safety features and a maintenance-free service concept.

There are 10 diesel-powered models in the AR Series with drum widths from 31 to 51 in. Centrifugal forces range from 2,925 lb on the AR-16 to 10,790 lb on the most powerful model in the series, the AR-40. Standard features include folding ROPS, dual frequency and amplitude, back-up alarms, pressurized water systems with dual filtration, noise attenuation, sliding seats, 100% side clearance through full flush drums, drum offset and lockable instrument panels.

The AR Series vibratory rollers (Circle 904) carry the MQ/Rammax brand name to complement Multiquip’s full line of light- and medium-sized compaction equipment, which already includes rammers, plate compactors, and trench and asphalt rollers.

Continuous paving

Bergkamp Inc., Salina, Kan., offers the M1 self-propelled continuous slurry seal/microsurfacing paver (Circle 905) that reduces the number of construction joints by receiving an endless supply of material while the machine is working. It is the only full-size continuous slurry seal/microsurfacing paver available and is ideal for large jobs and those with strict quality requirements.

Slurry seal and microsurfacing are among the most efficient methods of preventive maintenance for highways, roads and parking lots. The mixture aggregate, emulsion, water and additives is applied by the M1 in a smooth layer over existing pavement and can extend the life of the surface up to seven or more years. The main difference between slurry seal and microsurfacing is that slurry seal uses a standard emulsion, which requires evaporation to occur and sets in several hours. Microsurfacing uses a polymer-modified emulsion that produces a chemical reaction to force the moisture out and can set in less than an hour so traffic can return quickly.

The M1 is powered by a 335-hp Cummins diesel engine, has a hydrostatic drive system that can be controlled by either the front or rear operator station and wet disc brakes. The operator stations can be accessed from both sides of the machine and have handrails to protect the operator. The front operator station also has dual-driver stations, a detailed instrument panel and provides easy visibility of the aggregate hopper. Aggregate is delivered to the pugmill by a belt-over-chain fed conveyor, which eliminates slippage while the steep-hopper walls minimize bridging problems. The hopper is equipped with an automatic sensor to shutdown the system if it runs out of aggregate.

Customer satisfaction

Responding to customer demands for greater performance and productivity, BOMAG, Kewanee, Ill., has introduced the new 4413 self-propelled asphalt paver (Circle 906) featuring more engine horsepower, a redesigned undercarriage and improved operator ergonomics. The new 4413 paver is powered by a 60-hp Cummins A-series water-cooled diesel engine that offers approximately 40% more output torque than the engine on the previous model.

The 4413 includes an exclusive load-sensing hydraulic system that saves on fuel consumption by delivering power only when needed. Even with this power-saving system, the new paver can push asphalt feeder trucks while maintaining working speeds up to 160 ft per minute.

The 4413 paver offers paving widths ranging from 8 to 13ft, making it ideal for driveway, parking lot, asphalt repair and resurfacing applications. Designed to hold up to 7.5 tons of asphalt, the high-capacity hopper provides long operation intervals with fewer refills.

Asphalt technology

Also available from BOMAG is the BW190AD-4 AM tandem vibratory roller (Circle 907), which delivers continuously optimized compaction performance, regardless of operator experience, thanks to its Asphalt Manager technology. A special front drum designed to work with the Asphalt Manager system automatically measures and controls compaction performance. As the materials become stiff, Asphalt Manager begins to adjust the angle of the drum’s output energy from fully vertical to fully horizontal. This helps ensure that optimum compaction results are achieved while avoiding asphalt-damaging over-compaction.

The BW190AD-4 AM offers 79-in.-wide drums and feature slanted drum support legs, high curb clearance and a clear view of the entire drum surface. A fuel-efficient 131-hp Deutz water-cooled diesel engine powers the BW190AD-4 AM. The front drum delivers 35,550 lb of centrifugal force in high frequency (3,000 vpm) and 55,575 lb of centrifugal force in low frequency (2,400 vpm). The maximum centrifugal force provided by the front drum is 35% higher than units without Asphalt Manager, allowing the roller to complete compaction in fewer passes.

The rear drum of the BW190AD-4 AM produces 24,525 lb of centrifugal force in low amplitude/high frequency (3,420 vpm) and 37,575 lb of centrifugal force in high amplitude/low frequency (2,760 vpm). Independent drum vibration control allows the roller to handle a variety of lift thicknesses and applications ranging from granular bases to Superpave.

Smooth compaction

Ingersoll Rand, Davidson, N.C., recently introduced the DD-22 and DD-24 double-drum asphalt compactors for light- and medium-only applications. Both compactors feature a number of innovations that enhance overall performance. The DD-22 (Circle 908) has a drum width of 39 in. and an operating width of 5,400 lb, while the DD-24 (Circle 909) has a drum width of 47-in. and an operating weight of 5,725 lb. The front and rear drums on both compactors protrude beyond the frame, making it easier to compact around the obstructions without the chassis getting in the way and giving operators a clear view of drum edges.

The DD-22 and DD-24 double-drum units are built to produce the right combination of amplitude, centrifugal force and frequency to maximize daily productivity. Both compactors provide the choice of automatic or manual vibration and can operate in three modes: statically, front-drum vibration only or both drums vibrating. Two vibrating frequencies—3,300 and 4,020 vpm—allow the DD-22 and DD-24 to produce smooth, dense mats with a record number of passes.

Better paving performance

Ingersoll Rand also introduced the PF-6110 track-mounted paver (Circle 910), part of a new highway-class paver series utilizing global technology to provide solutions that increase paving performance.

Ingersoll Rand has a history of providing innovative paving products, and the tradition continues with the introduction of many new features that provide greater control or material flow. The auger system is now independent of the conveyor system. Each of the two auger and conveyor drives use sonic sensors for more precise handling of material. The conveyor system has chains that are automatically tensioned for proper performance and less downtime.

Hopper capacity for the series is 14.4 tons, giving each paver a practical production rate of 820 tons per hour. A 205-hp Cummins Tier 3 engine powers each paver in the series. The PF-6110 has a paving speed of 246 ft per minute and a travel speed of 11.4 miles per hour. The paver includes a 30-kilowatt generator with four 110-volt outlets. A technologically advanced hydrostatic direct-traction drive system on the paver eliminates 70% of all mechanical drivetrain components to reduce maintenance costs. The PF-6110 paver has a screed width of 10 ft and a maximum paving width of 26 ft.

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