 In fabulous Las Vegas and surroundings, a pavement slurry surfacing contractor is keeping image-conscious customers happy with peerless pavement surfacings, a consistent product, and a dedication to quality.
And it's doing it with motivated, uniformed crews, aggregate from its own pit, and high-performance laydown machines that keep projects moving and clients delighted.
"Las Vegas is different from other places we've worked because this town maintains its prestige," said Eric Reimschiissel, general manager, American Asphalt & Grading Company, Las Vegas, Nev. "Nearly all the pavements are crisp and clean. And it's not just the hotels and casinos; even the communities want that 'look'. So not only do we have to look good, but we have to adhere to stringent quality control programs instituted by the local governments, including material, hand work and seams."
That's why some of the slurry surfacing work AA&G does is strictly cosmetic, Reimschiissel said. "We'll put a single slurry seal over a parking lot, and all it's intended to do is make it look better," he said. "Our customers will pay for that prestige, because looks are a big thing out here."
All slurry seals in the Las Vegas area -- for both public and private sectors -- are latex-modified, Reimschiissel said. "A lot of that is because we have proactive customers who know the latex modifier helps the product withstand the scorching heat, provide longevity and enhance aggregate retention," he said. The latex is not derived from crumb rubber or tires, as may be seen in the Phoenix area, but is co-milled with the asphalt emulsion, dubbed LMCQS, for latex-modified cationic quick-set, with modifier incorporated a hefty 3 percent by weight, compared to 2 to 2.5 percent conventionally.
AA&G's fleet is made up entirely of Macropaver Model 12B slurry machines from VSS Macropaver, a division of Reed International, Hickman, Calif.
What are Slurry Seals?
Water-resistant slurry surfacings (or seals) seal minor pavementcracks and oxidized pavements, restore surface texture and skid resistance, correct raveling,reduce noise, and allow overlays whereweight restrictions and curb heights apply.
The Washington State Department of Transportation's Interactive Pavement Guide defines a slurry seal as a homogenous mixture of emulsified asphalt, water, well-graded fine aggregate, and mineral filler, with a creamy, fluid-like appearance as applied. Setting occurs very quickly – allowing traffic and access -- and the seal cures over a period of time. There are three configurations of slurry seals.
Type I (fine). This type has the finest aggregate gradation (most are smaller than the 2.36 mm/No. 8 sieve) and is used to fill small surface cracks and provide a thin covering on the existing pavement, WS DOT says. The International Slurry Surfacing Association recommends Type I aggregate slurries for low density/low wear traffic areas.
Type II (general). This type is coarser than a Type I aggregate slurry, with a maximum aggregate size of 6.4 mm (0.25 inches), and is used to treat existing pavement that exhibits moderate to severe raveling due to aging, or to improve skid resistance, WS DOT says. Type II aggregate slurry is the most common type used.
Type III (coarse). This type has the coarsest gradation and is used to treat severe surface defects. Because of its aggregate size, it can be used to fill slight depressions to prevent water ponding and reduce the probability of vehicle hydroplaning, WS DOT says.
Slurry seals are applied to an existing pavement surface by means of a spreader box linked to a slurry mixing unit or pug mill. Slurry is introduced into the spreader box, which then places the slurry coating over the width of a single traffic lane in a single pass as the mixer/spreader unit moves forward, sometimes at considerable speed.
Keeping Quality Paramount
AA&G differentiates itself from the competition on the basis of the  quality of its product, Reimschiissel said, but quality has to be achieved while also making money on a project. "High production rates are essential, while maintaining quality," he said.
"If you're laying 25 to 30 lbs. of Type III slurry per square yard, a quarter to a half-inch thick, you lay a lot of material, but you don't get a lot of area covered. So the faster the material can come out, the more area you can cover, and after all, that's how we get paid. If you can have a machine that's half or one-third faster than what someone else's will place, it makes a big difference in what you can get done in a day."
"Every contractor should put down a quality product," said Okeda Goodloe, slurry crew supervisor for AA&G. "That's our bottom line. The market is tight no matter where you are, but when you cut corners, it hurts all contractors. And we don't cut corners.
“A quality mix is a uniform mix that's not runny, with a beautiful texture," Goodloe said. "When your box and drag mop goes over it, a beautiful texture will result. You can go too fast, and depending on the aggregate and the oil, you will not have a good placement. The machine is only as good as the operator."
Goodloe said a number of clues to a failing placement are evident when the operator looks into the box, where slurry is mixed before deposition on the pavement. "Looking in the box, the operator will see a number of clues," Goodloe said. "If the mix is separating, the aggregate and oil will not be bonding, instead, they will be running away from each other. If there is too much water, some will be floating at the top. If there are inconsistencies, the operator will see it in the box before it gets to the pavement."
And once in place, indications to problem placements may be evident. "Clues to a bad placement include rippling, which indicates the truck went too fast," Goodloe said. "The operator won't see it, because he's looking in the box, but the squeegeemen or supervisor will see it."
Streaks or scratches can be caused by a number of issues. "You can have oversized aggregate caught in the box," Goodloe said. "Or if you work eight hours and the product is curing really fast, pieces can adhere to the burlap drag and that will cause streaks. If it’s a scratch the squeegeemen can take it out by hand. Most good operators will sense that something is going wrong and they will stop and raise the box to correct whatever is causing the scratch."
Slurry Sealers Start Early
Slurry sealers start early. Typically, Goodloe said, his day will start at 4 a.m., as he gets loads of oil placed in AA&G's tankers for that day's work. In the meantime, another worker will be onsite at quarter to six, making noise, so residents will come out and move cars per the flyers they received earlier. "We like to give residents a 48-hour notice, although some cities require an initial notification weeks in advance," Goodloe said. "Twenty-four hours' notice is a little too close, as some residents will already have made plans."
The crew is normally at work by 6 a.m., warming the machines up. "On the storage trucks a water jacket runs from the truck motor," Goodloe said. "We start things up and within 20 minutes the water is running from the radiator to the jacket, heating up the oil. The hydraulics also need to be warmed up after sitting for 10 to 12 hours."
Crew Wedded to Each Other?
There's more to productivity than the machine; a trained crew is a critical component. "The machine has a lot to do with the productivity, but crew chemistry also has a lot to do with it," Goodloe said.
"The productive crew will know each other as though they're married to each other," he said. "Everybody has got to know what the other has to do. If John falls, if I know what he is supposed to do, I can cover for him. If the operator takes a vacation day, we don't miss a beat; I can call someone to fill in for me and I can hop on the back of the machine. Without the chemistry, we could have a machine that runs by itself, but we're not going to get production."
AA&G’s uniform of brown slacks, and orange short-sleeved shirt with embroidered nametag goes far in maintaining crew cohesion and projecting an orderly public image. "It's very important, because the public sees us every day," Goodloe said. "If we're there with beer logos on our shirts we're not projecting the professional image we want."
"I have the best people working for me," Reimschiissel said. "These guys are awesome. I pinch myself every day when I think about how good they are, and about their commitment to quality and productivity. You can't buy that kind of enthusiasm."
Keeping Crew Busy
Slurry seal is a relatively small part of AAG, but it's an important one, Goodloe said. American Asphalt & Grading has about 60 persons involved in the asphalt maintenance section, compared to about 1,500 overall. "Our division has four sealcoat crews, two slurry seal crews, two patch crews, plus paving crews and dirt crews," Goodloe said.
The firm operates five Model 12B Macropaver slurry machines out of its Las Vegas region, with three under Goodloe's supervision. "I have three of the five, including our two newest machines,” he said. "On a Type III schedule we can put out up to 500 tons in an eight-hour shift, using three machines. That type of tonnage can be done on an arterial street; when you get into residential neighborhoods, it backs down to 200, 250 tons per day, because there's a lot more 'traveling', and you have to be more adept at dealing with curbs, gutters and cul-de-sacs. But on an arterial, it's a straight shot and you can just 'go'."
Typically Goodloe will rotate three machines to keep the lone spreader box busy. Anywhere from 10 to 15 workers will comprise the crew, depending on job size. Shuttlemen drive the empty spreader trucks back to the stockpile for recharging, and return to the production crew.
"We will have two squeegee or finish men, who clean up the edge line," Goodloe said. "We will have two to six people on traffic control. The line driver pulls the box while the operator on the back of the machine puts the quality product down. They're the two key guys, and they have to work in concert with each other. They're like husband and wife."
"All of our workers are important, and they all work as a team, but if you have to say which are the most important components, they have to be the operator and foremen," Reimschiissel said. "They can't do anything unless the other members of the team are doing their jobs, but the operator sets the pace. The operator has to be experienced. He can make or break you, because if he lays bad material, and doesn't know it, we will have to go back and make-good."
When he can, Goodloe cross-trains his crewmen so they are familiar with all aspects of a job and can pinch-hit for the others. "But cross-training is not easy, because we are here to make money, and speed is money," Goodloe said. "We can do cross-training on the smaller jobs, but never on the arterials."
True and Steady Lines
One key to slurry surfacing productivity is keeping the Macropaver true and steady. "The line driver puts a straight line on the edge of the slurry seal, and is one of the most important persons on the crew," Okeda said. "If he is crooked, it makes more work for everyone behind him, especially the squeegeemen. If he is straight, it will look good to the eye, and cleanup and repair are minimized."
Optimum speed is variable, and depends on the size of the project, he said. "Most inspectors like the machine to move between 300 and 500 feet per minute," Okeda said. "If you go faster than that they begin to squawk. Speed is dictated by the line driver and the box operator. If you have one location, 10 miles long, tonnage can be considerable. But if you're in a residential subdivision, with 20 streets to do, your production tonnage won't be so much and your day will be long."
Eliminating variables is a key measure to success, Goodloe said. "You need trained personnel," Goodloe said. "But you also need consistent product. One thing helping us maintain consistent product is that we have our own aggregate plant and our own pit, so we know our rock. And the Macropaver is a piece of equipment that's consistent, too. When we go to work, we know that we will be able to work. When I come to work in the morning, the last thing I have to worry about is my slurry trucks. I worry about supplies getting to the job, but my Macropavers are there."
Advanced electronic controls on the pavers also help maintain consistency and productivity, AA&G's Reimschiissel said. "The new controls on our trucks are all electronic, so you know exactly what you're laying," he said.
Equipment Keeps Projects Going
AA&G's fleet incorporates Macropaver Model 12B slurry machines from VSS Macropaver, a division of Reed International. The 12B is the fastest slurry machine in the world, with an application rate of up to 4.4 short tons (4 metric tonnes) per minute. "I'm familiar with all the manufacturers, and we looked around at different machines before settling on the 12Bs," Reimschiissel said. "We’ve had very good luck with them."
There are cheaper machines out there, but the Macropaver  difference is internal, he said. "In these difficult work environments we like a completely hydraulic machine -- without the chains -- like the VSS Macropaver," Reimschiissel said. "They're easier to maintain. And they're overbuilt, with improved electrical systems. The bottom is double-seamed; the steel is butted together and welded, then another lap is provided at the bottom. Emulsion tanks can be problematic; they can crack, or rust or wear out, and the double-seam takes care of that."
Macropaver self-loading of emulsion is another advantage, Reimschiissel added. "The way the machine self-loads is very good," he said. "When we are pumping emulsion, and our stock pump goes down, the machine can load itself. The pump on the machine will pull material out of the tanker and fill itself. There are times that that pump will go down, and the backup capability will keep us going. It's even more important when we're out of the Las Vegas area; If you're in Ely, Nev., and your pump goes down, what are you going to do? You're certainly not going to find another pump up there."
Despite their having to get used to it, Reimschiissel's operators now like the Macropaver's joy stick box control panel, Reimschiissel said, adding "With the joy stick, the operator can keep an eye on the slurry while being able to move the stick and control the whole machine."
One way a machine can boost productivity is through a high degree of uptime, Goodloe said. "The machine contributes through minimal downtime," he said. "Preventive maintenance here is essential. We do our share of preventive maintenance, but the machine has to be good to begin with. And our Macropavers are good machines."
And in the rare times the machine will need field service, the machine's modular construction helps keep a project going. "It's nice to be able to slide our conveyor belts and pug mill out,” Reimschiissel said. “We keep spare conveyor belts and pug mills in our facility, so if there is a failure in the field, rather than bringing the Macropaver in and have the machine down for a day, we can just pull the old pug mill or conveyor out, and put another one in. We just pull up, take the top out, replace the part, and keep going."
About the VSS Macropaver
The VSS truck-mounted Macropaver® has gained a worldwide reputation for flexibility, high production and low-cost performance. The Macropaver applies all slurry and polymer-modified microsurfacings with equal ease.
Consistent quality is accomplished throughout the production with automatic sequencing, a feature pioneered and perfected by VSS. The Macropaver can easily double the application rates of competitive conventional machines, with average outputs of 2,727-3,636 kg/min. (3-4 short tons/min).
Macropaver features the finest quality components, and no chain or sprocket drives, according to the manufacturer, VSS Macropaver, Hickman, Calif. The 12-cubic-yard Model 12B featured in this article includes automatic start/stop materials sequencing, automatic aggregate finish shutdown sensor, three-way Teflon-lined steel valve self-loading system, anti-syphon water load system, heated emulsion pump (hot water supplied by truck radiator), flow meters for water and additives, direct drive jackshaft (no chain-drives), integrated cement hopper with built-in agitator, variable speed cement feed system interlocked to aggregate output, pavement fog sprays and joint sprays, automatic variable amplitude hydraulic hopper vibrator, quick cleaning emulsion basket strainer, and side debris dump box.
The product is known for its rugged build, dependable performance in a punishing environment, reliability, ease of operation, and productivity. The Macropaver benefits from the half century of experience derived from originator Valley Slurry Seal as a pavement maintenance contractor. |
