This paper deals with the scaling effects in uniaxial tensile tests of fibre-reinforced cement. For this purpose dogbone shaped specimens were produced in two different sizes. The small dogbone size was scaled in 3 dimensions with a factor 4. Not…
This paper deals with the scaling effects in uniaxial tensile tests of fibre-reinforced cement. For this purpose dogbone shaped specimens were produced in two different sizes. The small dogbone size was scaled in 3 dimensions with a factor 4. Not only the size of the specimens was scaled, the basic materials were scaled as well. A fine-grained cement and straight steel micro fibres were used for the small specimen and 4 times larger cement grains and fibres were used for the larger dogbones. The specimens were cast in a way that ensured fibre alignment in the loading direction. For the uniaxial tensile tests freely rotating supports were used and during the test the surface of the specimen was scanned with two high-resolution digital cam- eras. These pictures were correlated and with this displacements and strains at the surface could be calculated. Further the fiber distribution and alignment were analyzed in a cross-section close to the crack. Although the size and the material were scaled, the reuslts show a size effect, this can be explained by the hydration prod- ucts, that can not be scaled.