The robotic arm lays out the “knitting pattern.” Empa researchers are investigating different patterns in a number of test series. Credit: Empa
Empa scientists are investigating how roads could be reinforced with simple means and recycled easily after use. Their tools are a robot and a few meters of string.
A robotic arm lays out a string in a mandala-like pattern on a bed of gravel. What appears to be a contemporary art performance is basic research that explores new ways in road construction. On the one hand, robot-assisted construction techniques for road building are being tested that have so far only been used in structural engineering. On the other hand, a new type of mechanical reinforcement is intended to change the typical structure of the road surface and thus to help save valuable resources in future or even to recycle road surfaces altogether.
An idea from structural engineering The idea originates from a project of the Gramazio Kohler Research lab at ETH Zurich. Here the project was actually raised as an art and research project. Pillars piled up purely from strings and gravel demonstrated that outstanding stability can be achieved by simply interlocking the gravel with a thread – without any cement as a binder! Laboratory tests showed that gravel pillars with a height of 80 cm and a diameter of 33 cm can withstand a pressure of 200 kN, which corresponds to a load of 20 tonnes.
Asphalt also consists of rocks of various sizes and a binder, bitumen. Thus Martin Arraigada and Saeed Abbasion from Empa’s «Concrete & Asphalt» lab transferred this concept to road construction: “We want to find out how a recyclable pavement could be produced in the future. To do this, we are using digitalized construction methods in road construction for the first time,” explains Arraigada. A string-reinforced road surface that does not require bitumen promises a number of advantages. Since bitumen is extracted from crude oil, air pollutants are released during production and also later during use.
What’s more, it makes asphalt susceptible to cracking and deformation and, on top of that, impermeable to rainwater – this too could be overcome. For the researchers, it is also conceivable that rock could be used that is otherwise not suitable for road construction, but is less rare. Last but not least, the process allows for a rollable and recyclable pavement.
A string and loose gravel The two Empa researchers are using various experimental setups to test solutions for the above-mentioned aspects. The robotic arm plays a central role. It places the string in a programmed pattern on the layers of gravel stacked on top of each other. For the mechanical tests, five of these layers of gravel and thread are placed on top of each other in a test box, with the floor of the box covered with a rubber mat that fixes the whole package to the ground. It simulates the deformable bed, to which the pavement is applied. The fact that the string is exactly the same as the one used by every Swiss citizen for bundling waste paper shows that Empa researchers are breaking completely new (and cost-effective) ground here.
Mechanical tests and computer modeling
The gravel-thread package is then loaded with a rotating plate and with pressure. This load test shows: By entangling the individual gravel stones with the thread, the package can withstand a pressure of 5 kN – half a tonne – without the stones moving much. Normally, the binder bitumen performs this task in asphalt. Dynamic load tests with rolling pressure, similar to the extreme conditions road pavements have to withstand, are soon to be carried out.
In parallel to their lab experiments, the researchers model everything in 3D on the computer using the Discrete Element Method (DEM). This should reveal the displacement of individual stones and the tensile forces acting on the thread – something that cannot be investigated in the lab. In addition, different patterns and mesh widths and their effects on the stability of the pavement will also be examined in more detail.
The research of Martin Arraigada and Saeed Abbasion has not yet resulted in a final product that is ready to be used in road construction. However, their research provides a lot of innovative potential to get closer to a recyclable and possibly rollable road pavement with simple means.
Original Article: Knitting roads
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Robot-assisted road construction
- XPeng 1024 Tech Day Unveils Smart EV Technologies and Mobility Ecosystem
Launched in early 2021, Navigation Guided Pilot (NGP) for highways, the core function of XPILOT 3.0, has assisted ... new road-capable model will feature a lightweight design, and a foldable rotor ...
- Franciscan Health Crown Point now offers robotic lung surgery
Franciscan Health Crown Point is offering robotic lung surgery to patients ... The da Vinci system improves on early video-assisted thoracoscopic surgery technology with a high-definition 3D ...
- Surgical Robots Market to surpass US$ 16,875.6 Mn by end of 2028, Says Coherent Market Insights
Robotic surgery was first developed in order to overcome the shortcomings of manual-assisted surgery and to improve the capabilities of surgeons doing open surgery without any assistance.
- In the pipeline: Albany region health care construction projects
A couple of significant health care construction projects around the ... Surgical technology includes the ROSA robot-assisted knee surgery system and Hana surgery tables for hip replacement.
- Covenant High Plains Surgery Center becomes West Texas' only ambulatory surgery center to perform robot-assisted total knee replacement surgery
Dr. David Shephard announced today the successful completion of West Texas' first outpatient robot-assisted knee replacement surgery at a free-standing ambulatory surgery center (ASC) using the ...
Go deeper with Google Headlines on:
Robot-assisted road construction
Go deeper with Bing News on:
- California agency says shredder site needs cleanup
SA Recycling should “investigate the extent of soil ... DTSC claims its own investigations have “found metal shredder residue called light fibrous material on the pavement, in pavement cracks, on ...
- Metal Recycler Ordered to Clean Up Pollution at Port of Los Angeles
After finding evidence that toxic material traveled off-site, the state Department of Toxic Substances Control ordered a metal shredding facility on Terminal Island at the Port of Los Angeles to stop ...
- Pa. to Pave Road With Asphalt, Recycled Plastic Mixture
The Pennsylvania Department of Transportation is collaborating with other state agencies on a new pilot project that will use a mixture of asphalt and recycled plastic from landfills to pave part of a ...
- State highlights collaborative plan to pave roads with recycled plastic
Continued ability to reuse asphalt millings in future recycled-asphalt pavement applications. “DEP is proud to support this project in partnership with PennDOT through the Strategic Recycling ...
- Wolf Administration Highlights Collaborative Pilot to Pave Roadway with Recycled Plastic
Officials from the state Departments of Transportation (PennDOT), Conservation and Natural Resources (DCNR), Environmental Protection (DEP), and General Services (DGS) today highlighted a pilot projec ...