Title:
The effect of fibres in UHPFRC beams with longitudinal steel reinforcement
Author(s):
Norbert Randl; Tamás Mészöly
Publication:
Symposium Paper
Volume:
310
Issue:
Appears on pages(s):
181-192
Keywords:
UHPC, UHPFRC, steel fibres, fibre reinforcement, cracking, high-grade steel reinforcement.
DOI:
Date:
3/17/2017
Abstract:
In a research project funded by the Austrian Research Foundation (FFG), ultra-highperformance fibre-reinforced concrete (UHPFRC) mixtures were developed and optimized.
Compression tests, uniaxial tension tests and several small-scale four-point bending tests were performed and the full constitutive law was derived. A series of 10 large-scale beams with a span of 3 m and an I-shaped cross-section was subsequently produced and tested in a fourpoint setup, where the reinforcement amount and the fibre content were varied. The tensile strength of the longitudinal reinforcement was 800-1100 MPa. Several circular openings were foreseen in order to facilitate potential installation crossings. In the tests with flexural failure
at ultimate load level, a pronounced ductile behaviour was observed. Cracking and crack
widths were controlled in a satisfying way by the longitudinal reinforcing bars and the fibres
as well. Apart from the mostly observed bending failure mode, two beams with increased
longitudinal reinforcement and 2% fibres exhibited diagonal tension failure in shear.
Regarding the ultimate load, in the tests with shear failure the fibre contribution was much
more significant than in the tests with bending failure.