Sensors act as early-warning system for concrete structures

Sensor technologies can be used to detect a wide range of inputs, from temperature and light to air pressure and ultrasonic waves. Across engineering disciplines, they are used by faculty members to collect data needed for groundbreaking work in energy, health care, manufacturing, infrastructure and more. Engineering researchers, it seems, are putting sensors everywhere.

Dr. Moe Pour-Ghaz

CCEE associate professor Dr. Moe Pour-Ghaz uses electromagnetic sensors to study the durability of reinforced concrete materials and structures and fiber reinforced polymer (FRP) composites for use in civil infrastructure.

The “sensing skin” he designed can work as an early-warning system for concrete structures by measuring things like damage, the presence of damaging chemicals, strain and temperature. This data can point to small problems that may become larger problems, allowing a quicker response to damage in everything from nuclear facilities to bridges.

This skin is an electrically conductive coat of paint that can be applied to new or existing structures. Electrodes are applied around the perimeter of a structure. The sensing skin is then painted onto the structure, over the electrodes. A computer program runs a current between two of the electrodes at a time, monitoring and recording the electrical potential at all of the electrodes on the structure. This data is then used to calculate the sensing skin’s spatially distributed electrical conductivity. If the skin’s conductivity changes, that means the structure has cracked or been otherwise damaged.

Recent work will expand the skins’ capabilities from being used on flat, straight surfaces to allowing their use on three-dimensional structures of unusual shapes. Pour-Ghaz’s research group has collaborated with Aku Seppänen’s group at University of Eastern Finland in developing this technology.

 

This story was originally published by the NC State College of Engineering.