The understanding of internal alterations in the structure of concrete constitutes an essential link in gaining better explanations for the bearing and deformation performance of concrete. For the detection of internal alterations a combination of indirect and direct methods is…
The understanding of internal alterations in the structure of concrete constitutes an essential link in gaining better explanations for the bearing and deformation performance of concrete. For the detection of internal alterations a combination of indirect and direct methods is applied. The indirect ultrasonic trans- mission technique provides the opportunity to measure throughout the testing procedure. With the integral pa- rameter ultrasonic attenuation it is possible to detect alterations of different dimensions in the structure of concrete due to mechanical loading. Significant differences between the tested frequency ranges were de- tected for alternately increased and decreased loading. It is possible to explain this phenomenon with altera- tions in the interfacial zone between coarse aggregate and matrix. For the visualization of the alterations dif- ferent direct techniques are applied in order to verify the indirect observations.