Title:
Strain Rate Effect on Bending Behavior of New Ultra-High-Performance Cement-Based Composite
Author(s):
Edouard Parant, Pierre Rossi, Eric Jacquelin, and Claude Boulay
Publication:
Materials Journal
Volume:
104
Issue:
5
Appears on pages(s):
458-463
Keywords:
cement-based composite; impact behavior; multi-scale fiber reinforcement; strain rate effects; ultra-high-performance concrete
DOI:
10.14359/18901
Date:
9/1/2007
Abstract:
The synergetic behavior of fibers at different scales is the main feature of the multi-scales fiber-reinforced cement-based composite studied in this paper. This material can be considered elastoplastic with strain hardening in tension. To cover a large range of loading rates, two dynamic tests were carried out using four-point bending test devices on thin slabs: a hydraulic press and a block-bar device. Experimental results showed that the modulus of rupture increased by 25% in the range of quasi-static loading rates (1.25 × 10–4 to 1.25 GPa/s [18.1 to 1.81 × 105 psi/s]), and was quadrupled for loading rate superior to 500 GPa/s (7.25 × 107 psi/s). Direct comparisons with ultra-high-performance cement-based matrix (without fibers) and other fiber-reinforced concretes (FRCs) studied in literature indicated that this new material is more sensitive to strain rate effects than all previously studied cement-based materials. The multi-scales reinforcement, especially the microfibers, amplifies the strain rate effects in the matrix by improving stress transfer within it. The uniaxial tensile strength increased by approximately 1.5 MPa/log10 unit (2.2 × 102 psi/log10 unit) in the range of quasi-static loading rates.