From time to time, we ask our members “What’s New?” The group of short responses may interest you. Also, you will find more information about AMAP’s upcoming Conference & Workshop from February 11 – 13 in Rancho Mirage CA.
Executive Director, Association of Modified Asphalt Producers
Determining the Quality of Asphalt Emulsions by Size and Zeta Potential
Asphalt binder emulsions have proven to be an environmentally friendly, energy efficient and cost-effective alternative to hot asphalt binder mixtures. They are typically used for roadway resurfacing as an adhesive for post-applied aggregate chip. Typically composed of bitumen, water and an emulsifying agent or surfactant, asphalt emulsions provide the required stability and application characteristics for optimum performance. Malvern Panalytical has several tools that can provide valuable metrics for production and characterization of asphalt emulsions. Two tools highlighted below include the Mastersizer, which uses laser diffraction to determine particle size distribution, and the Zetasizer which uses electrophoretic light scattering to measure zeta potential.
Figure 1 shows the results of four different asphalt emulsion samples measured on the Mastersizer 3000. Per ISO 13320:2009, laser diffraction data reports three sizes of parameters: D10, D50 and D90 (Table 1). These D-values (D10, D50 & D90) are the intercept for 10%, 50% and 90% respectively of the cumulative volume. The other statistical number that is commonly used for laser diffraction is SPAN which is calculated by (D90-D10)/D50. SPAN will increase as particle size distribution width broadens. The Mastersizer 3000 was able to clearly differentiate four asphalt emulsion samples with similar particle size range and median size.
Zeta potential is a common metric of colloidal stability and formulation applications. The higher the zeta potential, the more stable the colloid. Colloids with low zeta potentials tend to coagulate. Factors that can influence the zeta potential include charge state, pH, additive concentration, ionic concentration, behavior of emulsifiers, and other dispersion conditions. In which case, emulsion droplets can be stabilized through a steric or charge repulsion mechanism. Figure 2 shows the Zeta potential distributions for several formulations that exhibit a higher absolute value for zeta potential.
Asphalt Testing Solutions & Engineering (ATS) Focuses on Evaluating Rejuvenators, Workforce Development and Professional Presentations
With nation-wide attention on balanced mix design, asphalt producers can find innovative ways to utilize RAP while maintaining performance. Two different case studies by ATS, one on analyzing rejuvenator performance of Blacklidge’s ReGen™ and Kraton’s PolyRejuvenator ™, are published on its website, while an internal study comparing about a dozen different rejuvenators is currently being conducted in the lab.
Industries around the country are placing an emphasis on workforce development and the asphalt industry is no different. To help support this initiative, ATS recently hosted a group of forty-five high school students and a dozen college students at its labs. ATS will also participate in the Women in Transportation Initiative (WITI) with the University of Florida in the Spring semester. Female students will participate in weekly rotations to develop specialized knowledge of the asphalt industry. ATS will partner with Duval Asphalt during week five of the program (asphalt production) where students will tour the asphalt plant and ATS labs.
Team members at ATS love to share their knowledge. They recently offered lunch-and-learn presentations around the state to educate groups in different areas of the industry. Engineering firms and industry associations have requested presentations on Pavement Preservation which include a focus on modified emulsions and binders. This December, Tanya Nash, an ATS Pavement Materials Engineer, will present at the following events:
- American Sports Builder Association (ASBA) Technical Meeting in Florida — speaking about asphalt additives
- Mid-Atlantic Expo in Virginia — “Obtaining Mix Performance with High RAP and Modified Binders”
- 2020 AMAP Conference — “Balanced Mix Design 201” and “Handling Modified Binders (Contractor’s View).”
Stay up to date with all ATS projects and events here:
Recycled Plastic in Modified Asphalt
Dow is working with several industry associates to use recycled plastic in modified asphalt to pave four roads in Midland County, Michigan as well as parking lots at the Global Dow Center in Midland and at Saginaw Valley State University. This is the second phase of Dow’s recycled plastic road pilots in North America, following the successful construction of two roads at Dow’s Freeport, Texas facility. The goal is to help develop new end-use markets that maintain the value of recycled plastics. Enabled by Dow ELVALOY™ RET asphalt modification technology, these projects achieve the following:
- Use more than 10,400 lbs. of recycled plastics, equivalent in weight to more than 769,500 plastic grocery bags.
- Cover 5.5 lane miles of asphalt roads and 30,500 square yards of parking surface.
- When combined with the Freeport, Texas pilot earlier this year, Dow’s recycled plastic road projects in North America have incorporated more than 12,086 lbs. of plastic, equivalent in weight to approximately 889,500 plastic grocery bags.
“As we work towards our 2025 Sustainability Goals, we’re harnessing the power of innovation and collaboration to help build a plastics circular economy that retains the value of plastics while working to minimize plastic waste in the environment,” said Julie Zaniewski, Dow’s North American sustainability director for Packaging & Specialty Plastics. “We’re excited to see this pilot demonstrate the viability of ELVALOY technology and recycled plastics modified asphalt for potential use in U.S. public roads.”
“The preliminary performance results of our asphalt road projects containing recycled plastics have been promising and we’ll continue exploring collaborations to advance recycled plastic modified asphalt roads as a viable end market for used plastics,” said Nishant Karamchandani, Dow’s North American Packaging & Specialty Plastics infrastructure marketing manager. “It’s a strategic way we can use our business to help advance the circular economy.”
Read more at dow.com
Americas International is now distributing Sasobit!
Sasol has chosen to have a portion of their asphalt additives business managed through distribution and chose Americas International to distribute and represent Sasobit in the asphalt additives market in the US.
With a typical dose of 1.5% Sasobit – key benefits include:
- Reduction of asphalt viscosity, allowing a wider workability window;
- Extends the construction season in cooler months;
- Increases softening point while decreasing penetration point;
- Longer haul with workability to provide placement and compaction;
- Placement of thicker lifts and opening traffic sooner.
Americas International, Inc. is proud to join forces with Sasol in providing sales of Sasobit.
With warehouses strategically located throughout the US, as well as a highly dedicated staff, Americas International provides prompt and efficient services for all Sasobit needs. The Sasobit Technical Specialists will continue to provide the same world-class service customers have relied on in the past. Americas International will provide information and assistance so that together we can fully support our customers.
Contact Amanda at Americas International for more information on our full product line serving the asphalt market including Therminol heat transfer fluids! Email: email@example.com Phone: 888-503-3855
Prism Worldwide Introduces New Recycle Elastomer Technology
PRISM™ Worldwide is an innovation company driven to advance sustainable products and practices through science and technology. They are ending the wasteful disposal of end-of-life tires (ELT) through a first-in-its-class technology that converts used tire rubber into fully functional, cross-linkable rubber and rubber-derived polymer.
PRISM’s™ patent pending process is a result of thirty years of research and refinement. It creates a chemical and physical reaction that realigns the critical sulfidic bridge in thermoset rubber. The process keeps all the valuable polymer, linkages, and carbon black intact. This new process creates a like-new thermoplastic rubber called PRISM™ Thermoplastic Rubber (PTR™).
By providing not only the rubber, but all the chemical bonds too, PTR™ provides a new product with numerous applications including road technologies, roofing materials, new tire materials, and consumer products made from engineered rubber. PTR™ based materials, including the PRISM Enhanced Asphalt Rubber (PEAR™) created by interfusing PTR™ with asphalt binder, have proven to last longer, produce lower carbon emissions and can be re-recycled!
PRISM™ has also created new technologies and equipment that extend the life of roads and highways by releasing the existing binder in asphalt and preparing it to be interfused with PEAR™ ready mix material. PEAR™. When mixed with the original binder, it creates a sulfidic bonding of the non-oxidized binder material. And just like that, you have PTR™ recycled materials seamlessly blended into any pavement repair.
Welcome New Members in 2019
21st Annual Conference & Workshop Just 9 Weeks Away