Experimental investigation on crack detection using imbedded smart aggregate

As an important aspect in the asset management of the existing concrete bridges, a proper evaluation of the conditions of the concrete, especially the width and the distribution of cracks in the concrete structure turns out to be rather important. Conventional approaches usually require onsite investigations and are labour intensive. On the other hand, it has been recognized since long time that the elastic wave transfer properties through solid can reflect the change of properties inside the material. Smart Aggregate (SA) is a newly developed ultrasonic sensor based on this effect. Casted into the target structures, these sensors make it possible to detect the change of ultrasonic wave transfer properties and evaluate the damages of the structures from the inside. This paper presents a structure condition assessment strategy by making use of SA grid through a lab test on a scaled specimen.