How can we turn asphalt paving into a data-driven process for optimizing both the construction process and make better predictions on the road lifetime? A recently renewed road on the UT campus now has in-built fiber optics sensors for monitoring both the construction and use of the road. It is a Living Smart Campus project led by Seirgei Miller of the faculty of Engineering Technology.
The campus experiment is part of a larger project in which the major road construction companies in The Netherlands participate, aiming at professionalization of the sector. It is called Asphalt Paving Research & Innovation and is led by André Dorée, Seirgei Miller and Farid Vahdatikhaki of the department of Construction Management & Engineering.
“Paving asphalt still is a process based on implicit knowledge, through years of experience of the crew working on the road”, Seirgei Miller explains. “By collecting data from the very beginning, however, we can adapt the process in real time and give instructions to the road workers. Apart from that, using the data, we will be able to monitor long term road behaviour.” There is a clear reason for doing so: the high demands on quality and lifetime. While in the past, a guarantee period of three to five years was common, seven to ten years is now standard, even moving upward. Miller already did extensive measurements, together with his students. For example, by combining hi-res GPS, cameras and infrared scanners. “We know a lot about asphalt products, we can create ideal mixtures in the lab. But the conditions during paving can determine the road’s ability to resist extreme conditions like frost. Mechanical tension during the construction phase may lead to shorter lifetimes and wear.”
Sensors inside the road
The renewal of some UT campus roads gave rise to the question if it would be possible to install sensors between asphalt layers. These sensors start by monitoring the paving process, and they monitor road behavior in the years after. “The campus is an ideal testing ground for this. In general, contractors and road authorities are reluctant when it comes to installing sensor equipment in the asphalt layers. We already have a number of monitoring points in the region, these are RFID-sensors you have to read out on the spot. This is time-consuming and even not very safe, at busy roads. Thanks to the Living Smart Campus project, we can experiment with sensors that can be read out continuously, and in the asphalt. These are both fiber optics and RFID sensors.” High asphalt temperatures are not a problem for fiber optics. Of specific interest is the way the road behaves during cycli of frost and thaw, and the way it bends when there is a car passing. RFID sensors additionally detect parameters like temperature, for a comparison with the fiber optics data.
Student projects
Already during road construction, the sensors started giving a vast amount of valuable data. In the coming period, it will be exciting to see in what way the road develops and what relations can be detected between the paving process and long-term road behaviour. The campus is an ideal testing ground for this, Seirgei Miller expects to have projects for students from various backgrounds.
The project website of ASPARi is www.aspari.nl
Living Smart Campus
The asphalt monitoring experiments of ASPARi are part of the Living Smart Campus programme of the University of Twente. This programme aims at using the full potential of the campus, as a 'living' lab. Living Smart Campus has experiments in research, teaching and support, the campus community is actively involved. More info at www.utwente.nl/livingsmartcampus.
