How to Be the Plant Everyone Buys From

Editor’s Note: For 2024, AsphaltPro Magazine allows experts in the industry to share how to expand your operations to the next phase of business. Are you ready to start making your own hot-mix asphalt? Let’s turn to some professionals who have equipment, services, software and tenure to help you expand to mix design, production, hauling and more. This month’s installment looks at the best practices you can employ with the storage silo to offer customers quick, quality asphalt mix for their paving projects.

If you’re in the hot-mix asphalt (HMA) industry, you know one of the game-changing inventions of last century was the storage silo. During his “Asphalt Plant Efficiency” presentation during a World of Asphalt People, Plants and Paving session in Nashville in March 2024, Greg Renegar, the vice president of customer success for Astec Industries, Chattanooga, discussed the benefits of planning ahead with your storage silos in mind.

If your “why” is to provide mix for both customer and in-house crews, you’ll want to plan ahead for overnight storage of appropriate mixes as you build your new plant. During his presentation to the World of Asphalt audience in March, Astec’s Greg Renegar reminded attendees the plant that can start loading out customers first thing in the morning will be the plant everyone flocks to.

As he explained, even if you have older components you’ve been unable to update the past few years, you can operate efficiently if you maintain those parts, tighten up your environmental footprint, and follow best practices, such as optimizing the use of storage silos.

Notice that’s “optimizing” the use of storage silos. Not every mix design is ideal for the suggestions to come, and we’ll talk about those.

“If you are using very low absorption aggregates, it may lead to a high film thickness and the mix is more prone to drain down.”—Steve Jackson

Solve Asphalt Plant Odor Issues

Store It for Fast Startup

Renegar’s presentation included a side-by-side comparison of operations you might be able to share with your production team to showcase what’s optimal and what’s not.

Amazing Producer ABC

Using old technology

  • Starts loading out of prefilled silos at 6 a.m.
  • Starts up the plant at 8:30 a.m.
  • Runs two to three mixes on various jobs, with enough trucks for the day
  • Runs all day with changeovers but no mid-streams
  • Fills the silos at the end of the day for tomorrow’s early customers

Expand into Production: Plant Ticketing Software Basics

Struggling Producer XYZ

Using new technology

  • Starts making mix at 6 a.m.
  • Runs two to three mixes on various jobs, short of trucks
  • Mid-streams at 8:30 for 45 minutes
  • Runs another 300 tons and finishes for the day!
  • Cleans out
  • Gets a call at 10:15 a.m. for a 150-ton parking lot job
  • Fires back up at 11 a.m., runs 147 tons, then mid-streams while paving foreman figures the last bit needed

One of the two producers in our examples is using new technology for its efficiency and sustainability but isn’t using best planning strategies. Renegar shared plants that start and stop more than three times per shift use up to 20-35% more fuel than they do when they run steadily. These percentages are published in the National Asphalt Pavement Association (NAPA) publication QIP-132.

You can probably monitor the effect of starting and stopping on your own fuel use. By using the storage silo to take up the slack and prevent starts and stops, you keep a steady, even production. Renegar stated Astec’s most successful customers are the ones who use long-term storage capabilities to become more profitable.

Think about it.

Because 95% of breakdowns occur at startup, you have a leg up on the day even if unplanned downtime hits you at first light. You also have a leg up on your competition on the other side of the county if your plant already has mix in the silo while Producer XYZ is still getting fired up.

Renegar explained it this way: “Storage in multiple silos plus planning allows FOB customers to get in and out quickly in the morning. Serving the FOB customers better than your competition will result in more business.”

Expand Into Production: Navigate the Permit Process

Design Your Storage

This isn’t rocket science. But it does require forethought. Renegar cautioned producers on some reasons you might not want to store mix overnight. For example, lack of planning from your customers could result in wasted mix. There’s no point in producing a hundred tons of state mix at 300 degrees if your top five customers will show up wanting a less-pricy mix produced at 340 degrees.

If you don’t have proper heating systems in place, you run the risk of losing mix temperature. There are companies making electric heating elements that can be placed in silo cone packages to take the fear out of overnight storage. These entities might not make the silo itself, but are experts in the manufacture of electric heating components and provide these to OEMs like CWMF Corp., Waite Park, Minnesota, who then assemble the complete silo.

Even with the concern of temperature under control, you want to consider the mix design you’ll store. Renegar listed the “fear of storing polymer” as one of the reasons producers shy away from filling up the silo overnight or over a weekend. Folks in the field echo his concern when it comes to open-graded mixes due to a phenomenon known as drain down. This is when gravity pulls the liquid asphalt cement (AC) away from the aggregate and down toward the silo cone.

Steve Jackson, the vice president of plant operations and sustainability for NB West Contracting, Pacific, Missouri, spoke of this phenomenon in stone matrix asphalt (SMA) mixes. “The worst mix that I have seen for drain down is SMA,” Jackson shared. “That is why some agencies are reluctant to remove the cellulose fibers even when you add ground tire rubber or reduce the mix temperature.”

He gave an example. “I remember an SMA project where we filled a silo, and that was all the mix that we made for the night. The first sample, from the bottom of the silo, had high AC and 1.5% air voids. The second sample, toward the top of the silo, had low AC and 7% air voids. We made the mix extra hot because it was going to spend a long time in the silo.” The expensive lesson he shared was having to mill out that tonnage and replace it.

How to Become Your Own Hot-Mix Supplier

“SMA, open-graded friction course and other gap-graded mixes are the worst for this phenomenon,” Jackson continued. “They also usually have specified minimum asphalt contents. If you are using very low absorption aggregates, it may lead to a high film thickness and the mix is more prone to drain down. When Joe Schroer (NB West’s construction materials engineer) worked at MoDOT, he evaluated some of those mixes, and started calculating the volume effective binder, and approved some of the SMA mixes with less than the minimum spec requirement AC content of 6.0%.”

In other words, there’s hope for “fixing” the gap-graded mix so it can be stored overnight for quick loadout in the morning, if you’re willing to work with it.

Malcolm Swanson, industry consultant and president of e5Engineers LLC, Chickamauga, Georgia, shared his thoughts. “Coarse graded mixes, SMAs, any mix with little surface area will tend to drain down. That is a major reason for adding fiber to a mix. Fiber adds surface area without changing gradation. The added surface gives the AC a place to hang on.”

“If the state allows the contractor to design their own non-gap-graded mixes, then the mix has the absolute minimum asphalt content, so they are less likely to drain down,” Jackson said. “If there are mixes that specify a minimum asphalt content, then I would be careful. Take a look at the aggregate absorption as well. We typically use aggregates with 1% or lower water absorptions in our high type mixes, these are mixes that we try to drop the mix temperature as low as possible to prevent drain down.”

For producers looking to optimize the use of the storage silos, it’s possible to adjust the mix design and temperature to ensure you have exactly what your customers are looking for first thing in the morning. It might take a little forethought and planning, but the producer who plans ahead is the producer who can optimize all the components for a tight environmental footprint, an efficient operation and a plant that all the customers flock to.

Relieve These Top 8 Pain Points When Laying Out Your New Plant

Editor’s Note: For 2024, AsphaltPro Magazine allows experts in the industry to share how to expand your operations to the next phase of business. Are you ready to start making your own hot-mix asphalt? Let’s turn to some professionals who have equipment, services, software and tenure to help you expand to mix design, production, hauling and more. This month’s installment from CWMF takes an overarching look at the plant footprint.

If you’re considering or planning on building a hot-mix asphalt (HMA) plant or expanding on your existing operation, you likely have a question or two. Or maybe a couple hundred. That’s because it’s complex and highly specialized. And not everyone who recognizes the marketplace opportunities of asphalt and paving is necessarily already an expert in what it takes to build an efficient asphalt production facility. Getting this massive undertaking right requires vast experience and deep expertise. Here are a few things to consider when you start planning your new asphalt plant.

1. Stationary or Portable and Tons per Hour (TPH).

The choice between a portable and stationary asphalt plant depends on various factors, including project size, duration, location, environmental regulations and mobility requirements. Stationary plants are best suited for large, long-term projects, while portable plants offer flexibility and mobility for shorter-term, varied, or remote projects. You will also need to determine how many tons per hour your market requires. Bigger isn’t always better when considering the overall investment.

Expand into Production: Plant Ticketing Software Basics

2. Equipment Placement.

Determine the optimal arrangement of key equipment within the plant. When designing an asphalt plant, two crucial factors demand careful consideration.

Available Real Estate for Stockpiles

The extent of available property plays a pivotal role in determining the layout of the plant. To optimize both cost and efficiency, it is essential to focus on key features such as minimizing the distance and ducting required between the drum and the baghouse. Additionally, when positioning the asphalt cement (AC) tank package, minimizing the amount of piping that needs heating is paramount for enhanced efficiency.

Truck Traffic Flow in the Yard

Determine the optimal arrangement of key equipment within the plant. The goal is to minimize the distance virgin and recycled materials must travel through the plant and ensure efficient material flow.

When planning for current and future cold feed and recycled asphalt pavement (RAP) bins, it is imperative to be mindful of the traffic flow. The available real estate will dictate the optimal angle and configuration for the plant.

Even if you have plenty of real estate to spread out plant components for optimum visibility and multiple stockpiles of on-spec material, you want to focus on such things as minimizing the distance and ducting required between the drum and the baghouse. Keep these efficiencies in mind when designing your layout. Photos courtesy of CWMF Corp.

3. Control Room.

Design a control room with a clear view of the entire plant operation. This allows operators to monitor equipment, adjust parameters and respond to issues. CWMF offers integrated industrial automation and control solutions for asphalt plant equipment. We can provide the engineering, manufacturing, installation, start-up, and training to get you up and running at peak efficiency.

4. Install Electric and Plumbing.

Establishing the required equipment for your plant is one thing, but defining your needs to get it up and running is an entirely separate process that requires significant planning and preparation. Be sure to team up with an equipment manufacturer that can walk you through each step of the process.

Plan Ahead! Implement safety measures, such as clear traffic patterns, proper signage and emergency response plans. Getting the right signage in the right places is part of your successful plant layout plan, not only for traffic flow and proper stockpile management, but also for emergency preparedness.

5. Environmental Impact Assessment.

Evaluating the potential environmental impact of your new asphalt plant is critical. You’ll need to make sure you are following the local environmental regulations and obtaining the necessary permits. Consider implementing a pulse jet or reverse flow baghouse, such as CWMF’s Dust-Eater.

The baghouse dust collector is considered the “lungs” of a plant. When the plant cannot breathe effectively, it negatively affects production. This is an essential part of asphalt plant operations, along with the dust control system employed upstream to help retain and return usable dust particles back into the drum mixer rather than putting them immediately into the exhaust airstream.

Expand Into Production: Navigate the Permit Process

6. Zoning, Land Use Regulations and Permitting.

Understanding the local zoning laws, land use regulations, and permitting that govern where industrial facilities like asphalt plants can be located is incredibly important.

7. Safety and Emergency Preparedness.

Prioritize safety for both employees and the surrounding community. Implement safety measures, such as clear traffic patterns, proper signage and emergency response plans. Ensure that fire protection systems, hazardous material handling, lockout/tagout, and confined space entry procedures are in place.

How to Become Your Own Hot-Mix Supplier

8. Replacement Parts.

Once your plant is up and running, are you prepared for untimely breakdowns? Team up with a company you can trust to get you the replacement parts you need ASAP. The CWMF sales and service teams are ready to work through determining what you need to get your plant up and running, whether for the first time, during scheduled maintenance, or after unplanned downtime. Never underestimate the importance of the parts that make up the whole or the value of the professionals who go the extra mile to keep your plant online.

CWMF has been a trusted company in the stationary and portable asphalt industry for decades. As a full-service manufacturing company, we engineer all our products to order, allowing us to serve as a full-service, end-to-end provider of asphalt plant solutions. We have the machinery and equipment you need, and a confident team working together to make this happen. This provides an exceptional experience for our customers, and for the dedicated team standing behind their products. We work hard not only to retain our reputation but to stay current on the latest industry trends and technologies.

Wally Olson is CWMF Corporation’s sales manager. For more information, contact him at (320) 251-1306 or visit cwmfcorp.com.