Einfluss der Faserzugabe auf die Streuung im Zugtragverhalten von Stahlfaserbeton

Influence of fibre addition on the scattering in the post cracking tensile behaviour of steel fibre reinforced concrete

Steel fibre reinforced concrete (SFRC) has been successfully used in certain areas of concrete constructions. However, the main area of application remains industrial concrete floor slabs. The large scattering in the material properties impedes the application for components with significant loads. Therefore, extensive experimental investigations on the scattering in the tensile post cracking behaviour of SFRC were carried out. The investigations include 4-point-bending tests on large-sized beams as well as standardized beams according to the German guideline for fibre concrete. The specimens differ in fibre amount, fibre length and type of fibre addition. After bending tests, the fibre orientation and distribution were determined along all specimens by using an opto-analytical method. The test results demonstrate that the fibre orientation is almost constant, while the fibre distribution scatters significantly. In bending tests as well as the opto-analytical analysis, the influence of the type of fibre addition is evident. Consequently, the scattering in the mechanical behaviour can be reduced by a suitable fibre addition and thus a more homogeneous fibre distribution can be gained.