The Future of Asphalt
You surely have traveled asphalt roads and that’s no surprise. Asphalt is the most common material used to surface roads and has several advantages. It creates a safe, quiet surface for driving, it can be laid down quickly and without complex machinery, and it is tough and can be easily repaired. It is a mixture of dark bituminous pitch with sand or gravel. While it can be strong, asphalt is known to degrade over time – opening as cracks at first and quickly expands. They can turn into potholes, the very commonly seen cavities on asphalted roads, dreaded by motorists.
While potholes can be repaired, it is not readily easy to have road repairmen sent to every crack or hole to make repairs every so often. It mostly takes time to get it done and when it does, the holes will surely reappear in especially busy roads time and again. A solution presents itself in the form of autonomous drones or other vehicles that are equipped with robots capable of 3D printing asphalt. These drones can be sent to repair cracks in their early stages.
In a paper entitled “3D Printing of Asphalt and its effect on Mechanical Properties,” a group of researchers develop an asphalt 3D printer. They constructed the 3D printer using a frame and control system from another 3D printer, the RepRap Mendel 90 built from flat sheets at 90 degree angles. Also printed was the extrusion nozzle, the extrusion nozzle assembly, the stepper motor housing, PCB and serial port clip.
Asphalt pellets were created using a hard grade of bitumen, cast in a machined mold at different low temperatures, from 100° to 140°C. Multiple different shapes of pellets were made, including standard test bars, their strengths compared to cast asphalt samples. The mechanical properties of the 3D printed and cast asphalt samples were very different. The cast samples showed the property of being directionally dependent, which implies showing different properties if stretched in different directions. The 3D printed specimens have 9x the ability to be stretched compared to the cast samples. This property is due to microstructural changes in the asphalt which result in crack-bridging ﬁbres that increase toughness.
This research shows that a 3D printer attached to a drone could be used not only to repair roads, but also hard-to-reach areas such as rooftops. These machines could fix minor damage before it turns into a major concern. It will save municipalities’ time and money and likewise, avoid accidents and damage to vehicles.
All Roads Lead to 3D Printing in Seattle
Your 3D printing company in Seattle looks forward to a brighter future for 3D printing in light of the many advancements in the technology. While road repair with 3D printing drones may be an area still under investigation, we still got a lot of great ideas for printing.