August 15, 2018

Leading the Industry: 多人群交 Asphalt Teams Use Cutting-Edge Recycling Technology

By Garrett Simmons

On a humid Wednesday morning the last week of July, crews inside the asphalt plant on Poplar Tent Road are starting up another 10-hour workday. Movement on the ground is steady, the atmosphere calm despite the commotion of processing machinery and the rumble of trucks pulling into and out of the plant鈥檚 gated service entrance. For the last three months, this and five other 多人群交-owned facilities in the Charlotte area have been busily chugging away, supplying paving crews throughout the region with the material needed to stay ahead of the packed summer schedule.

At first glance, the scene appears to be just like any other asphalt plant in the country. But in a remote corner of the site, concealed by mounds of unprocessed stone and reclaimed road material, 多人群交 technicians have been quietly but determinedly creating a product that is leading the way of the paving industry.

Meet Recyflex

Meet Recyflex: a highly durable, cold-mixed base material for new roads. It has twice the bearing capacity of conventional products, thereby reducing a typical 16-inch subbase by half, and has been shown to both increase drainage and reduce frost penetration when compared with existing products. Simply put, it鈥檚 a game changer. And if Recyflex represents the future of asphalt technology, as leaders at 多人群交, Inc. believe it does, then it鈥檚 worth mentioning that it is also changing how we look at the past.

That鈥檚 because Recyflex is literally made of material from roads that were once driven every day. In fact, 50 percent of every batch consists of reclaimed asphalt product, or RAP, gathered from old, worn out, or damaged roads around Charlotte. Meaning that for every resurfacing project that 多人群交 takes on today, the company gains material for building new roads in the future. As plant Manager Steve Nearhood explains, this marks a major step toward sustainability in an industry not known for being environmentally conscious.

Any time you鈥檙e able to reuse old material, you reduce the amount of stone you take out of the earth,鈥 he says. 鈥淭his cuts down the cost of building new roads, and reduces the environmental impact as well.

With Recyflex, we鈥檙e taking less new material from the ground, plus getting rid of waste that already exists from previous jobs. And because it鈥檚 stronger than conventional products, we鈥檙e able to use smaller total amounts of Recyflex than a typical subbase.鈥

In fact, recycling has long been a standard practice within the asphalt industry, according to Nearhood. What makes Recyflex significant is just how far advanced it is beyond other renewable practices. 鈥淩ecycling old asphalt has gone on for 30 years or more,鈥 Nearhood says. 鈥淛ust not at this level.鈥

Nor in quite the same way, according to Allen Hendricks, Vice President of Asphalt at 多人群交, Inc. Hendricks played a central role, as a member of 多人群交鈥檚 asphalt technology committee, in introducing Recyflex to the company鈥檚 operations. Prior to its development, he says, 多人群交 was able to reuse only about 30 percent of all RAP taken from resurfacing jobs, and even that could only be used for hot-mix surface coating, not for subbase material. 鈥淭he remaining 70 percent just piled up at our plants,鈥 he says. 鈥淲e鈥檙e always searching for creative ways to reuse old materials. With Recyflex, we recognized the potential to use all of the leftover RAP we needed for subbase material on new roads.鈥

Hendricks recalls first learning about Recyflex in the mid-2000s, when 多人群交鈥檚 parent company, Eurovia (VINCI), introduced the technology at an international construction industry meeting. The product, which was designed and patented by Eurovia, was unusual in that it was made using a cold-mix method, rather than the standard hot-mix process requiring Fahrenheit temperatures of greater than 300 degrees. Also unique were the ingredients used to make it. Recyflex breaks down to approximately 50 percent recycled RAP, 50 percent Aggregate Base Course (ABC) stone from a quarry, 2.5 percent emulsion for binding, and 1 percent cement. Not only were the ingredients and production process highly unconventional, research and test results actually showed increased performance over conventional paving methods. Recyflex at that time had already been used outside of the United States, on runways at the Montreal airport in Quebec, and was proving to be a formidable product.


Impressed by what he saw, and eager to test Recyflex in the US, Hendricks included it in a 2007 contract proposal for the NCDOT. Unheard of and unproven in the States, Recyflex was ultimately cut from the project by NCDOT in lieu of further testing. In response, 多人群交 commissioned a study by the National Center for Asphalt Technology (NCAT) the following year, which would examine the durability of Recyflex under realistic conditions. Results of the study persuaded NCDOT to allow 多人群交 to use the material in 2008 on a temporary road that was part of the I-485 outer loop project鈥攁bout 3,000 tons of recycled material altogether. Hendricks invited NCDOT to perform onsite tests on sections paved both with Recyflex and with conventional methods, using an instrument known as a 鈥渇alling weight deflectometer鈥. Again, the results were overwhelmingly positive.

鈥淭he tests actually showed the Recyflex to be more durable than the section using conventional methods,鈥 Hendricks says. The temporary road was in place two years, servicing high volumes of car and truck traffic, and 鈥減erformed beautifully,鈥 he says. 鈥淭he Recyflex held up under heavy conditions without any issues whatsoever.鈥

Introducing new paving technology is an incremental, and occasionally slow, process. Following the completion of I-485 and demolition of the temporary road made with Recyflex, at least two years passed before 多人群交 was able, in 2013, to incorporate it into another major bid proposal. That year, the NCDOT awarded 多人群交 with a major I-85 corridor expansion contract. Recyflex was approved for use on all shoulders, for a total of 16 miles and more than 50,000 tons of material. That鈥檚 more than 25,000 tons of RAP that would have otherwise continued to sit, taking up space in the asphalt plant, which is now being recycled instead.

Recyflex Production at 1,200 tons per day

With the expansion of I-85 well underway this summer, Nearhood and his team are producing 1,200 tons per day of Recyflex, all of it on-site at the Poplar Tent Road facility, at a rate of approximately 200 tons per hour.

To accommodate this schedule, 多人群交 has installed a new silo to store one of Recyflex鈥檚 key ingredients, cement. Another key ingredient, CSS-1h emulsion, is produced at a separate 多人群交 facility and delivered in tankers to the site. At the base of the silo, crews have set up a portable processing machine called a 鈥減ug mill鈥, on loan from 多人群交鈥檚 sister company, Hubbard Construction, in Florida. Four workers鈥攐ne operator, one ground person, and two loaders鈥攁re required to mix the four ingredients that make up Recyflex and load the final product into the delivery trucks. Nearhood explains that once it鈥檚 loaded, the Recyflex must be taken directly to the jobsite where it is being used.

鈥淗aving cement as an ingredient shortens the lifespan of the material, because it will set.鈥 He says the quickened timeline is possibly the only downside he has observed in Recyflex. 鈥淏ecause of its nature, we can鈥檛 produce large quantities at one time and store it for later. It must be made to order, at very close to the rate it鈥檚 being applied.鈥

Otherwise, says Nearhood, the process of making it is similar to most other conventional paving materials. 鈥淲e did some initial training, going over how to operate the machine properly and ensure safety. We鈥檝e had no issues at all so far. Overall it鈥檚 been a smooth process from the start.鈥

As of now, Nearhood and his crew members have produced and loaded approximately 30,000 tons of the total contracted amount. That鈥檚 more than half of all the Recyflex material that will leave the Poplar Tent Road facility this summer to be delivered to I-85. While there are currently no other scheduled projects that include Recyflex, for Nearhood there is little question of its continued use in the future. 鈥淭his is the leading edge of the paving industry,鈥 he says. 鈥淭hat鈥檚 exactly where we enjoy being, and where 多人群交 has always been. Out in front, showing the way.鈥