Self-Sensing Smart Roads

Lead Research Organisation: University of Cambridge
Department Name: Engineering

Abstract

Infrastructure is essential for the operation, prosperity and economic development of any society. As an important part of the infrastructure system, developing emerging technologies that could enhance the efficiency, safety, resilience and sustainability of the transportation system is more urgent than ever. The smart road system is a great example of such technologies. As roads age and deteriorate, maintenance and eventual replacement is needed to keep the road network functioning properly. The surface expression of failure is often sudden and damaging to proper traffic flow, requiring expensive reactive maintenance, but the road deterioration will have been occurring subsurface beforehand. Monitoring the deterioration and cracking within the road structure will allow maintenance or replacement to be planned and service lives of these valuable assets to be optimised. This research will focus on monitoring the deterioration of concrete elements within road structures to evaluate long-term changes in their condition through cracking.

Since there is no expansion joint in continuously reinforced concrete carriageway roads, during the concrete curing period, cracks develop at around 1m intervals. In service these crack networks can propagate through the concrete, reducing the life of the material. Rolled compacted concrete roads are becoming more common in the UK and have inevitable flaws in their concrete structure. While minor flaws during construction are non-problematic, if these grow during service, they will eventually lead to failure of the road structure. Monitoring the growth of small cracks within pavements is thus important to issue early warnings of failures due to such cracking behaviours. The proposed research aims on finding a way to monitor the degradation of concrete carriageway roads and rolled compacted concrete roads, and thus to issue early warnings of failure in service by embedding carbon nanomaterials in cement-based materials. As extra benefits, such materials may also be able to strengthen the road and be used for traffic monitoring purposes.

In the scope of the PhD project, a number of research stages would be considered. The initial step is material selection and development, which involves small-scale experiments on self- sensing cementitious samples embedded by various kinds of carbon nanomaterials such as graphite and graphene. Different tests including rheology, hydration, compression, bonding and three-point bending tests will then be conducted. Durability tests will also be considered to investigate how the material changes with time in the long term. Regarding the sensing capability, the electrical conductivity of the specimens will be monitored during the tests, which could provide the relationship between the electrical performance and the strain variation. The feasibility, interaction and effectiveness of the sensing systems could also be explored through large-scale tests and ultimately field trials which might be carried out in the future with the assistance of Highways England for full-scale applications. The data captured from the sensing systems at the end will feed the road's Structural Health Monitoring system by issuing early warnings of the road damage, which contributes to timelier and more accurate road maintenance as well as better safety. In addition, the interpreted data could also be linked to the road management system to minimise traffic congestion and disruption during daily traffic control.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S02302X/1 01/10/2019 31/03/2028
2485568 Studentship EP/S02302X/1 01/10/2019 30/09/2023 Xueying Wang