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Görüntü yöntemlerinin beton mikro yapısının ve çelik birleşimlerin deformasyon davranışlarının belirlenmesinde uygulanması

Güler, Murat
Sözen, Şahin
Özen, Murat
In this project, two different studies were conducted using digital imaging techniques. In the first phase, relationships between aggregate shape parameters and concrete strength were investigated. The relationships were sought using three mix design variables, i.e., aggregate gradation, maximum aggregate size and aggregate type. Cubical specimens were prepared under laboratory conditions and digital images were obtained from the cross section of each specimen to determine the aggregate shape parameters. Statistical analyses showed that all three mix design variables have significant effects on the concrete strength. It was noticed that the strength was more affected by gradation and aggregate type than by the other factors. The elongation factor was found to be a significant factor for the strength in the case of crushed aggregate. Also, the angularity seemed to increase the strength for smaller maximum particle size gradation. In the second phase of the project, the deformation behavior of steel connections under tensile loading was studied using the digital imaging techniques. A total of four different connections were tested within the scope of the project. Two connections were prepared by welding operation and the other two as bolted connections. The deformations were calculated from the image frames taken during the tensile tests of the connections. The calculated deformations were compared with the measured deformations using strain gages. The comparison was also made based on the results obtained from the finite element solutions. The analyses showed that the deformations obtained form the digital frames are in close agreement with the measured deformations as well as the calculated deformations from the finite element model of the connections. Hence, it was concluded that the deformation distribution for steel connections can be accurately determined using the digital imaging techniques without a direct contact to specimen surfaces.