Development and application of computed tomography in the inspection of reinforced concrete

As an alternative, THASA has developed, improved beyond the previous state-of-the-art, and applied over a decade, Reinforced Concrete Tomography (RCT), a non-destructive inspection technique of the highest precision, based on the use of gamma-rays. This technique has found a wide range of practical applications in buildings, bridges, under-water pillars, oil-filled ducts, statues and tunnels involving well over a thousand inspected structural elements. Beneficiaries of this technology are primarily civil engineers who are responsible for issuing technical reports on the condition of structures and need data to base their reports on. Port, highway and railway authorities rely on this technology to meet maintenance requirements. Construction companies interested in quality controlling the work of subcontractors, insurance companies and landowners are also beneficiaries of this technology. The ultimate beneficiary is the general public, through safety improvements of buildings and other structures, and also through less disruption, no noise and absolute cleanliness during the inspection procedures. An important initial motivation for the development of RCT was a tragedy that took place in 1992 at a beach resort on the Atlantic shore, 250 miles south of Buenos Aires. Four young people were killed when a balcony in a high-rise building where they were standing broke off. The ensuing investigation showed that just about every kind of malpractice was present: insufficient number of rebars of appropriate size, severe corrosion due to chlorine in the unwashed sand from the beach used in the construction of these balconies and steel bars placed too low. It was disturbing that there was no technical solution to detect these defects in balconies. RCT now provides the most complete answer to these kinds of problems.