Long-term performance monitoring of concrete structures using a novel graphene-based DURAble SENSor

Important results from the project

The aim of DuraSens project was the development of a structural sensor based on graphene-modified cement in order to monitor the curing phase as well as the structural performance of cementitious composites in service. The conductive graphene-modified sensors when embedded in concrete should capture setting, hardening and structural integrity. The overall goal of the project was that of the sensor to overcome any durability and stability issues that common performance monitoring systems face.

Expected long term effects

The novel graphene-based sensor consists of four highly conductive cylindrically-shaped electrodes. By utilizing graphene the conductivity of the cement-based sensors could be tailored. With the sensor cast into the concrete under investigation, electrical resistivity readings were captured and the setting and pore-structure development (hardening) was followed. Electrical resistivity development was recorded by use of a data logging system and which will enable monitoring of the structural performance and durability during service.

Approach and implementation

A large number of different combinations were tested to pin-point the appropriate mix that provided optimum electrical conductivity. Different mixing ratios of graphene, graphite and carbon fibres were tried and through a series of mixing optimizations the optimum conductive synthesis was used for the sensor. In sequence, the novel sensor was cast in concrete specimens to record resistivity during setting and hardening. The electrical resistivity of the concrete was captured with a data logger and with the sensor consisting of electrodes in a four probe configuration.