Quality of concrete condition assessment using several non-destructive techniques

Abstract

Non-destructive techniques (NDT) are often seen as a practical and efficient way to assess the material and structural condition of existing reinforced concrete structures. However, assessment cannot be reduced to measurement and interpretation, and asset managers and structural engineers often need a quantitative assessment. A combination of several techniques can offer precious help. This article intends to show what kind of improvement can be expected from such a combination. Examples are taken from a series of on-site case studies and laboratory experiments. The focus is on the assessment of water content and concrete porosity as these material properties are key factors regarding their present condition as well as their durability in an aggressive marine environment. Material variability, uncertainties on measurements and model error condition the accuracy of the parameter estimation. Their relative contribution to the quality of material assessment is analysed.