The connections between fresh and hardened state properties of fiber reinforced concrete and issues related to fiber dispersion have been a research challenge in the very last years. The topic is addressed in this work with reference to “self compacting” concretes with three different types of steel fiber reinforcement. Fresh state properties have been measured through the slump flow, V funnel and L-box tests. Plate specimens 1000x500x70 mm have been cast in such a way that the concrete flow was parallel to their long side. Beams 150 mm wide and 600 mm long and disks with a 150 mm diameter were sawn from the plates and tested respectively in 4 point bending and splitting. Beams have been cut with their axis either parallel or normal to the flow direction of the fresh concrete in the plate and the same happened for the diameter axis of preferential fracture in split disks. The results show a strong correlation between the fresh state properties, the dispersion and orientation of fibers, as influenced by the casting process, and the mechanical properties of the composite. An omni-comprehensive approach to the problem is currently under development aiming at a “design” of the material and of the casting process tailored to the dedicated application and to the anticipated structural performance.
On the connections between fresh state behavior, fiber dispersion and toughness properties of steel fiber reinforced concrete
DI PRISCO, MARCO;DOZIO, DANIELE;FERRARA, LIBERATO
2007-01-01
Abstract
The connections between fresh and hardened state properties of fiber reinforced concrete and issues related to fiber dispersion have been a research challenge in the very last years. The topic is addressed in this work with reference to “self compacting” concretes with three different types of steel fiber reinforcement. Fresh state properties have been measured through the slump flow, V funnel and L-box tests. Plate specimens 1000x500x70 mm have been cast in such a way that the concrete flow was parallel to their long side. Beams 150 mm wide and 600 mm long and disks with a 150 mm diameter were sawn from the plates and tested respectively in 4 point bending and splitting. Beams have been cut with their axis either parallel or normal to the flow direction of the fresh concrete in the plate and the same happened for the diameter axis of preferential fracture in split disks. The results show a strong correlation between the fresh state properties, the dispersion and orientation of fibers, as influenced by the casting process, and the mechanical properties of the composite. An omni-comprehensive approach to the problem is currently under development aiming at a “design” of the material and of the casting process tailored to the dedicated application and to the anticipated structural performance.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
