Title: Influence of the beam size on the residual strength of high performance fibre reinforced concrete
Author(s): Galeote, E.; Blanco, A.; Cavalaro, S.H.P.; de la Fuente, A.
Publication: Symposium Paper
Appears on pages(s): 40-49
Keywords: FRC, size effect, constitutive law, back-calculation, specimen dimension 40 fib Bulletin 95: Mechanical Characterization https://
The influence of size effect becomes an issue particularly relevant during the
characterization stage of concrete at laboratory scale. The dimensions of the specimens have a
direct influence on the strength measured and, therefore, selecting an appropriate specimen
size is of utmost importance in order to obtain representative results to be used in the design
of a structure. The notched beam test to characterize FRC is among the most extended
methods to determine the design parameters of the residual strength, mainly associated to
crack openings of 0.5 mm and 2.5 mm (fR1 and fR3, respectively). The main objective of this
study was to determine the influence of the beam dimensions on these two parameters. For
this, an analytical model able to reproduce the flexural behavior of FRC was developed.
Additionally, an experimental program involving high performance fibre reinforced concrete
(HPFRC) beams of dimensions 40x40x160, 100x100x400 and 150x150x600 mm was
conducted. The parameters of the analytical model were calibrated for each specimen
dimension using the results of the experimental program. The results show a clear influence
of the size of the specimen, mainly attributed to the area of fracture and the crack crosssection.