IMAGING OF CONCRETE STRUCTURES

Demand for the development of non-destructive testing (NDT) techniques for concrete structures has increased with the growing concern about the deteriorating condition of the World's infrastructure. Efficient a nd accurate imaging techniques are needed for a reliable evaluation of safety and serviceability of concrete structures. Although, presently , imaging is routinely used in various fields, implementation of these technologies in NDT of civil engineering systems, especially of concr ete structures, offers many challenges and requires additional develop ment due to the composite nature of the concrete material and the comp lexities of reinforced or prestressed concrete systems. This paper pre sents the basic principles of various imaging techniques associated wi th several NDT methods applicable to concrete structures. The techniqu es considered are radiography, radioactive computerized tomography, in frared thermography, radar imaging and acoustic imaging. Special consi derations regarding the applicability and accuracy of these techniques for the condition assessment of concrete structures are discussed, an d examples of imaging applications are given. (C) 1998 Published by El sevier Science Ltd.