EFS is a nondestructive crack inspection technology, similar in concept to a medical EKG, which is used to determine if actively growing fatigue cracks are present. An EFS sensor is first applied to the fatigue sensitive location on the bridge or metal structure, and then is injected with an electrolyte, at which point a small voltage is applied. The system subsequently monitors changes in the current response that results from the exposure of fresh steel during crack propagation. The EFS system consists of an electrolyte, a sensor array and potentiostat for applying a constant polarizing voltage between the bridge and sensor, as well as data collection and analysis software. The current response from the sensor array, which consists of a crack measurement sensor and a reference sensor, are collected, analyzed and compared with the system software. An algorithm, specifically written for this system, automatically indicates the level of fatigue crack activity at the inspection location.

Benefits:

• Increases the safety of the infrastructure and the efficiency of bridge management through better and more timely fatigue crack detection.
• Replaces “wait and see” approach by allowing immediate detection of growing cracks at known and unknown locations, as well as at repairs.
• More accurate assessment of condition ratings – extends the life of the structure through early identification and repair of growing cracks.
• Determines which cracks need immediate attention and which repairs can be deferred or eliminated; helps bridge owners utilize repair and rehabilitation funds more effectively.
• Repairs/retrofits can be verified immediately – no re-inspection needed.