Experimentelle Untersuchungen zur Streuung im Zugtragverhalten von Stahlfaserbeton

Experimental investigations on the scattering in the post cracking tensile behaviour of steel fibre reinforced concrete

Steel fibre reinforced concrete (SFRC) has been successfully used in Europe for over 30 years in certain areas of concrete constructions. Its applications range from shotcrete and prefabricated concrete products to monolithic basements, tunnelling and waterproof elements. However, the main area of application remains industrial concrete floor slabs. Therefore, extensive experimental investigations concerning the scattering in the tensile post cracking behaviour of SFRC were carried out at Institute for Structural Concrete, Graz University of Technology. The investigations include 4-point-bending tests, long beams and large-sized cellar components. The results of the bending tests clarify the large scattering in the tensile post cracking behaviour independent of fresh concrete consistency and fibre length. The fibre distribution and orientation along the long beams, which differ in fibre length and manufacturing method, was determined by an optoanalytic method. While the fibre orientation is almonst constant in all beams, the number of fibres in the sections exhibits larger scattering. To consider realistic conditions a basement and two rising walls were manufactured and the fibre distribution and orientation in them were investigated. It could also be detected, that the fibre distribution scatters strongly, in contrast to the fibre orientation which is almost constant.