Increasing mobility is a growth motor for industry and the economy. But in the future, mobility will have to be more environmentally compatible. This applies not only to vehicles but the traffic system. Evonik Middle East Africa recognized this trend and offers sustainable solutions for road markings with high longevity.
Every gram of weight saved means greater fuel economy and that protects the environment. The same principle that applies to cars and motivates the car industry is becoming increasingly important in the construction and repair of roads, which are subject to more and more stress around the globe. And the operators primarily government agencies regularly have to spend a great deal of money on road maintenance.
The established tool for studies that determine whether products actually display an improved environmental performance is the Life Cycle Assessment (LCA). Evonik Middle East Africa spotted the trend toward greater sustainability and eco-friendly technologies early on and conducted an LCA (in accordance with ISO 14040/14044) on the product DEGAROUTE®, a reaction resin for road markings. The LCA showed that road markings with greater longevity can make a valuable contribution to environmental and climate protection.
Study examines the environmental impact of four material technologies
The LCA study factored the entire value-added chain, from the raw materials, through production and use, to disposal or recycling. Transportation and packaging materials were also considered. This study investigated the environmental impact of applying and maintaining road markings a middle stripe and two side stripes on a two-lane, one-kilometer section of roadway.
The assumed traffic volume of 10,000 to 15,000 vehicles per day is that of a typical highway. Because such a road has to be resurfaced after about ten years, the marking-related environmental impact was calculated for a ten-year period.
Depending on the technology used, the markings may have to be re-applied multiple times over this period. The study analyzed the four most important material technologies used for road markings in Europe: solvent-based and water-based paints, thermoplastic and cold-plastic systems.
Because solvent- and water-based paints generally display a shorter useful life, they are primarily used for roads with low traffic volumes. In contrast, thermoplastic and cold-plastic systems offer significantly greater longevity and are suitable for busy roads and highways. With a content of 20 to 40 percent, DEGAROUTE® is a key component of cold-plastic formulations.
Safety aspects determine longevity
The critical factor that determines the efficiency and longevity of road markings is that they have to be clearly visible at night and in bad weather conditions such as fog and rain. Traffic safety is ensured only when drivers can fully distinguish the side and middle stripes. This is why all markings contain tiny glass beads on the surface, which reflect headlights so that the eyes perceive a bright white marking.
But the amount of adhesion of the glass beads in the polymer matrix differs depending on the material technology. On busy roads, the embedded particles are scratched over time or even lost completely through tire wear. But lack of visibility, especially at night, can have potentially serious consequences. This is why the markings have to be renewed on a regular basis. The frequency and environmental impact of the re-application of road markings was also part of Evonik’s LCA study.
A long useful life is good for the environment
The LCA demonstrated that the degree of environmental damage for example, CO2 emissions and the associated global warming potential is directly connected to the longevity of the road markings. Of the four systems studied, cold-plastic technology displayed the highest longevity: the road markings had to be re-applied only four times within ten years.
In contrast, the solvent-based systems had to be repaired each year to maintain the markings. This means significantly higher material consumption. While hot-spray plastic offers high longevity, this degree of durability is reached only with high material consumption per application, which makes it a cost driver.
Cold-plastic technology offers another advantage when it comes to agglomerate markings, which have a fine structure two to three millimeters high. This type of marking is used primarily on highways because it offers higher visibility, especially on wet streets. Thanks to its three-dimensional structure, raindrops run off the glass beads and light reflection is preserved. The thermosetting properties of this marking system make the three-dimensional surface structure extremely strong and long-lasting.
This is why a complete side or middle stripe never has to be replaced during maintenance. Refreshing the surface is all that is needed. With the help of spray technology, all that is needed is a layer of marking material 0.3 millimeters thick to serve as anchor for a fresh layer of glass beads. This makes the road markings clearly visible again, even when it is dark and wet, and extends their useful life by another two years.
Less new material is required, therefore, to restore functionality and that protects the environment. The markings can be renewed in this way up to three times a factor that was also included in the LCA study. As the results of the study demonstrate, renewing the markings using spray technology is an ideal solution for satisfying both safety and environmental requirements.
