On the Influence of SCC Rheology and Casting Method on Fibre Distribution – Data and Experience from Large Scale Tests

The paper is based on results from an ongoing Norwegian R&D project with the overall goal to generate data that can be used to overcome remaining obstacles for a wider use og fibre reinforced concrete (FRC). One such obstacle is the unsafety concerning fibre distribution and orientation. A specific goal is therefore to provide data that can be used to recommend casting procedures and belonging concrete rheology limits that give reliable and predictable fibre distribution in wall elements. A number of walls of 2.5 x 7 m, were cast of both self-compacting concrete (SCC) with various rheology and vibrated concrete (VC) and placed using pump and hose with 1–2 drop zones. The results indicate a rather narrow SCC rheology window for success in terms of fibre distribution in a wall, and that pouring from two positions improved the fibre distribution only slightly. The results confirm also that the influence of mixing and transport on fibre distribution is far less important than concrete rheology and casting method.