Jan 04, 2024
How To Make Warm Mix Asphalt Work At Your Plant
INGEVITY IN THE NEWS
Developed in the 1990s, Warm Mix Asphalt is anything but a new technology. However, there’s still a fair amount of stigma associated with it in the road building industry, despite the Federal Highway Administration’s pivot in 2010.
For the possibly uninitiated, however, WMA as a process was first experimented with and pioneered in the United States, in 1956 at Iowa State University by Professor Csanyi. Although the modern foaming techniques utilized today were developed in the European market in the late 1990s. It wasn’t until 2010, when the Federal Highway Administration (FHWA) incorporated WMA as part of its Every Day Counts project, that the process began to find a bigger foothold in domestic markets. Around the same time, chemical additive technologies were introduced and now make up for 60% of all WMA produced.3
The process is defined by the FHWA as asphalt produced anywhere between 30 to 120 degrees below the standard hot mix asphalt (HMA) production temperatures, and that ranges anywhere from 300 to 350 degrees.4
However, according to the Asphalt Pavement Industry Survey on Recycled Materials and Warm-Mix Asphalt Usage 2021 created by the National Asphalt Pavement Association (NAPA), “The weighted average temperature reduction achieved among asphalt mix produced at reduced temperature was 23.5 degrees.”3
That appears to indicate that, on the weighted average, the production of WMA is not falling into the FHWA defined range. The NAPA survey went on to show that almost 84 percent of the WMA produced fell between 10 and 30 degrees reduced production temperature. That means the vast majority of WMA made in 2021 potentially, just reached the minimum end of the temperature spectrum.5
While even a small temperature reduction still has energy and environmental significance, who are the asphalt producers that are sitting well above that minimum temperature reduction threshold? Who is taking the big swings? Maybe more importantly, how do they set about to make the transition from HMA in the first place?
Really Big Swings
When Carmine Pace, the Quality Control (QC) Manager at Hubbard Construction’s Tampa and Lakeland Florida asphalt plant locations, decided to bring WMA to their facilities, he chose to do it in what might be considered an unconventional way.
“In January 2023, I went to management, and told them that I wanted to try it,” Pace said, somewhat expecting a little pushback. To his surprise, they were nothing but supportive and encouraging of the experiment. “They told me to go for it, and to see how it might work for us.”
When Carmine Pace, the Quality Control (QC) Manager at Hubbard Construction’s Tampa and Lakeland Florida asphalt plant locations, decided to bring WMA to their facilities, he chose to do it in what might be considered an unconventional way.
“In January 2023, I went to management, and told them that I wanted to try it,” Pace said, somewhat expecting a little pushback. To his surprise, they were nothing but supportive and encouraging of the experiment. “They told me to go for it, and to see how it might work for us.”
Hubbard’s parent company VINCI has set Group Environmental Goals to reach by 2030, and WMA is a big step to achieving those reduction goals. [sic]
“We were already using Ingevity’s Evotherm® WMA additive as a liquid anti-strip, we just were not taking advantage of its full potential,” Pace said. “Now, we are seeing just how low we can get the warm mix target temperature. We’ve pushed it down as low as the mid 260s, and we had no issues while doing some straight pulls.” That’s nearly a drop of 45 degrees from their original HMA productions temperatures, which would result in an astounding ~75 percent drop in fumes and odors released.1″
Read the full article here
