New Horizons Open For California Slurry Surfacing Contractor

A Southern California slurry surfacing contractor is expanding its customer base – while boosting productivity and performance -- by upgrading its fleet.

          Until recently, Fontana, Calif.-based American Asphalt South, Inc. had confined its operations to municipal, county and private sector slurry work. But equipment acquisitions in late 2005 will enable it to tackle state slurry surfacing jobs that had been outside its reach, and work more confidently with difficult materials.

          American Asphalt South's market base includes lower-level government agencies and private-sector clients, but hasn't included state DOTs. "We work for the municipalities, the cities, the counties, but don't do a whole lot of state work," said Tim Griffin, operations manager, American Asphalt South, Inc. "As much as 95 percent of our work is for the cities and counties, and 5 percent is private work."

          But that likely will change as the firm expands its horizons. "We’ve hardly  done anything for states," Griffin said. "But part of the reason why we bought upgraded equipment was our goal of doing state work as it comes in our area, which is anything south of Fresno."

          To these ends American Asphalt South acquired two truck-mounted Model 12B Macropavers from VSS Macropaver, Hickman, Calif. They replaced decades-old equipment that were subject to continuing breakdowns and service interruptions.

          "We looked at our equipment and realized that our daily maintenance costs, and loss of productivity due to breakdowns, were too high," Griffin said. "Getting brand-new machines like the Macropavers would allow us to maintain a constant production rate and minimize maintenance costs, which would more than offset the price of the machines. I have used new equipment before, but we generally bought used equipment. Once I showed management how new equipment would save us money – and make us money – they gave me free rein to get what we needed. Our goal at American Asphalt South is to be the best slurry company around. We had the best people, so I bought the best equipment I could find, and now we have the best of both."

          Input for this machine came from existing employees, literature, and conversations with other contractors. “From everything that I heard and seen, the Macropaver was the best purchase for us,” Griffin said.
          The leap from old technology to new was startling for the American Asphalt South crews. "We went from manual calibration and 'sticking' of oil and water levels, to automatic readouts to see how much product we've used," Griffin said. "Now we have digital readouts that tell us everything that has been used. We can set the machine up, dial in the exact settings, and we know exactly what we are laying. This enables us to lay material a lot easier than with the old machines."

          Moreover, the new equipment lets crews place more complex mixes with greater confidence. "Some materials can be difficult to lay," Griffin said. "These machines lay materials a lot easier; you can place components that we might have had issues with an older machine. But with these, you can mix those components and lay the product with no hassles. It opens up our capabilities."

          "The new machines are allowing us to bid more work, because there are restrictions on some projects where we need to have a machine like the Macropaver in order to bid the job," said Lyle Stone, senior estimator. "We could not do that with our old machines, because they did not meet the requirements. It opens us up to bidding of more work, and increased production, because these machines can lay more in the same amount of time. And that will result in us being more competitive in the marketplace."

What are slurry seals?

          Water-resistant slurry surfacings (or seals) seal minor pavement cracks and oxidized pavements, restore surface texture and skid resistance, correct raveling, reduce noise, and allow overlays where weight 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.

          American Asphalt South firm usually provides conventional Type I and Type II slurry seal and rubberized slurry seals to their clients, but also can perform Type III surfacings, Stone said. "We don't run into a lot of Type III aggregates required on projects in Southern California," he said. "Caltrans will put out Type III projects, but they're usually in the middle of the state, going north."

          Slurry seals are very popular in western states, and the year-round operating climate in Southern California guarantees an abundance of projects, and of competitors. "We have the right temperature range without the frequent rainfall you get in the Midwest and Back East," American Asphalt South's Griffin said. "We can slurry-seal the year-around in Southern California."

          But with that kind of activity, profits can be razor thin, and incremental productivity increases are essential to enhancing the bottom line. Fortunately, within a week of acquisition, the firm's new Macropavers were exhibiting verifiable increases in productivity for the contractor. "We've been increasing production by one or two loads a day, because the equipment is more efficient," said Richard Entrikin, controller.

          "The machines have a larger capacity and can hold more," Stone said. "They hold more aggregate, more oil, and more water. Therefore we can run the same number of trucks per day as with the old equipment, but the trucks will lay 10 percent more material in about the same amount of time, which is huge."

          Griffin said the two new machines essentially are doing the work of three replaced machines. "Instead of having three machines on a job site, we are doing the same job with two," he said. "We're actually using less equipment for the same job. We've taken a complete machine out of the equation, with associated labor and fuel cost savings."

          In addition to the productivity improvements, the new equipment helps American Asphalt South track material costs. "We have better monitoring of our expenses," Entrikin said. "There is one less truck in the field. It's a lot easier for the operators and the supervisor to do their jobs."

          “We know exactly what we’re laying,” Stone said. “A big problem I’ve seen with slurry seals is inconsistency between trucks, creating a ‘rainbow’ effect on a street, in which one pass is a different color than another, and the next is different from that. With these machines, dialed in exactly, there is no reason for one pass to look any different from another pass.”

          And once the machine is set up, its operation is consistent, regardless of the crew or operator using it, Griffin said. “Once it’s set up for the mix design, any one of our crew should be able to operate it,” he said. “Trained, experienced operators will know certain tricks that will help them provide a superior laydown, but in theory, the nice thing about the machine is that once it’s set up, anyone should be able to operate it.”

          Also promoting improvements in productivity is the availability of service from the manufacturer. “Service and support has been great,” Griffin said. “I can call them today for something really ‘off the wall’, and within 48 hours it will either be in my hand, or we’ll have a plan for what will happen next. Everything I’ve asked them they’ve knocked out sooner than I expect. To me, that’s huge.”

          Microsurfacing is a mixture of polymer modified asphalt emulsion, mineral aggregate, mineral filler, water, and other additives, properly proportioned, mixed, and spread on a paved surface, as defined by the Foundation for Pavement Preservation. "Microsurfacing differs from slurry seal in that it can be used on high volume roadways to correct wheel path rutting and provide a skid resistant pavement surface," FP2 says.

          While American Asphalt South does not perform microsurfacing, the new machines give them that opportunity in the future.

          "We don't do any microsurfacing at this time," Stone said. "We now have the ability lay microsurfacing if we choose to do so. That's just one more way the machine opens up more markets for us. But the market is limited to Caltrans in our market area. Our goal is not to do microsurfacing, but to bid the additional standard slurry seal projects out there and increase our production."

          American Asphalt South has found that there is more to successful slurry sealing than high-performance equipment; for productivity, the equipment is no better than the staff that it is using it.

          "You have to have the right people, knowing how to use the equipment, doing the best job they can without cutting corners," Griffin said. "It's the right personnel, with the right attitude of the company, going out and doing the work properly. Everybody has the opportunity to lay slurry seal properly, in the proper range of specifications. Not everybody chooses to do so. But at American Asphalt South, doing so is our No. 1 priority. We want to make sure the client is extremely happy when we're done with the project, and having the right personnel, the right equipment calibrated in advance, and right materials, leads to a quality product in the field."
         

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 pavement fog sprays and joint sprays, automatic variable amplitude hydraulic hopper vibrator, quick cleaning emulsion basket strainer, and side debris dump box.

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