engleski

Non-Destructive Testing Methods for Concrete Structures Assessment

Paper describes non-destructive (NDT) methods for condition of concrete structures assessment with the accent at the most recent approaches. NDT methods are used for determination of certain characteristics of concrete, as strength, modulus of elasticity, permeability, stress and strains in structures. Finding and characterisation of hidden defects in concrete (segregation, cracks, etc.) and determining of position and state of reinforcement in concrete is second important application of NDT methods. Results are evaluated at non-direct way, by the measuring of material property, which is correlated with the looked property. NDT methods for the inspection of metals has been an accepted practice for a many years, but successful application of NDT methods to concrete is relatively new. The main reason is non-homogeneity of concrete, which makes testing results inaccurate. Successful application of NDT methods at concrete requires complex analysis and high experienced specialists. There is no specific code or standard that can be used as a guideline for the selection and application of suitable NDT methods. Test selection procedure may be based on a combination of factors as accuracy for given method, speed, non-destructiveness and cost. Each of testing approach has certain advantages and disadvantages, and the best opportunity is to use several testing methods and to make combination between them. In practice, first is visual inspection of possible corrosion indications. Second survey including NDT testing methods, electrochemical and non-electrochemical. Finally, destructive testing methods are recommended as a confirmation of results obtained with NDT methods.

concrete; non-destructive testing; assessment of concrete structures.

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