Title: Experimental study of shear transfer in polypropylene fibre-reinforced concrete using pre-cracked push-off specimens
Author(s): Ortiz-Navas, F.; Scaroni, L.; Navarro-Gregori, J.; Serna-Ros, P.
Publication: Symposium Paper
Appears on pages(s): 91-100
Keywords: Push-off, shear crack, PFRC, SFRC, Shear behaviour.
Shear transfer mechanisms in fibre-reinforced concrete (FRC) have been studied by many
authors based on push-off specimens. However, only few studies have used pre-cracked pushoff
specimens to examine the real shear and normal stresses transferred through the crack. In
this paper it is presented the experimental results of twenty-one pre-cracked push-off specimens
tested under direct shear. Specimens were manufactured using plain concrete (PC),
polypropylene fibre-reinforced concrete (PFRC), and steel fibre reinforced concrete (SFRC).
In PFRC and SFRC specimens, fibre was dosed in 10kg/m3 and 30kg/m3 respectively.
Nevertheless, both types of dosages were selected in order to provide similar post-cracking
behaviour to the specimens. Five types of pre-crack openings were set up (W = 0, 0.25, 0.50,
0.75 and 1.0 mm) by an external steel frame system that confined the specimens during the
tests. Afterwards, pre-cracked specimens were tested under direct shear where the crack
kinematic (opening and slip displacements) as well as stresses (shear and normal) were
recording during the tests. Finally, a comparison of behaviour between PC, SFRC and PFRC is
done. Experimental results show the ability of both fibres to increase shear stress as well as
shear stiffness in FRC specimens compared to PC ones. Moreover, it is evidenced that both
type of fibres provided similar shear improvements despite of being different in material and