Title:
Strength and Size Effects in Fiber Reinforced Materials
Author(s):
S. Cattaneo and G. Rosati
Publication:
Symposium Paper
Volume:
216
Issue:
Appears on pages(s):
63-78
Keywords:
acoustic emission; Electronic Speckle Pattern Interferometry (ESPI); fiber; fracture mechanics; high-performance concrete; size effects
DOI:
10.14359/12892
Date:
10/1/2003
Abstract:
The objectives of this paper are to present experimental evidence and to offer an explanation of the size effects on structural strength and post-peak behavior observed in high strength concrete beams under three point bending. The materials had an aggregate/binder ratio of 1.5, a microsilica/binder ratio of 0.1, a water binder ratio of 0.22, and different steel reinforcing microfibers content (0-1 and 2% by volume). Beams of different length-to-depth ratio and different sizes were considered. The tests were monitored with interferometric measurements that detect the full displacements field on the surface and with acoustic emission that reveals inelastic phenomena related to damage that develops in the specimen. Test results showed that when steel fibers are introduced in the concrete mix, the size effects on the structural strength and ductility usually are less pronounced. However, the considered size ranges show that the fiber length should be chosen adequately relative to the size of the specimen. The proposed model shows that an asymptotic value of strength is reached sooner in fiber-reinforced material.