African Design Magazine ADM #42 July 2018 | Page 51

TECHNOLOGY
SIMULATION OF THE FLEXURAL RESPONSE OF
ULTRAHIGH PERFORMANCE FIBRE-REINFORCED
CONCRETE WITH LATTICE FRACTURE MODEL
ChunpingGu, Qiannan Wang, and Wei Sun, “Simulation of the Flexural
Response of Ultrahigh Performance Fibre-Reinforced Concrete with
Lattice Fracture Model,” Advances in Civil Engineering, vol. 2018,
Article ID 7894192, 8 pages, 2018.
T
he flexural response of ultrahigh
performance fibre-reinforced
concrete (UHPFRC) was simulated
based on the lattice fracture model.
Fibre was modelled as separated beam
that was connected to the matrix with
interface beams. The simulated results
were compared with the experimental
results. Deviations occurred at the late
stage of the strain-softening period. But
both the strain-hardening behaviour
and multicracking phenomenon were
observed in the simulation. The effects of
fibre orientation and fibre content were
studied with the lattice fracture model.
The flexural strength and toughness of
UHPFRC improved as the fibres were
aligned distributed or the fibre content
increased. The proposed model has
the potential to help with the materials
design of UHPFRC, and the limitations
of the model were also discussed in the
paper.
Introduction
Ultrahigh performance fibre-reinforced
concrete (UHPFRC) was initially invented
in 1980s in France [1, 2]. In the revised
recommendations on UHPFRC published
by AFGC (Association Francaise de
Génie Civil) [3], UHPFRCs are defined
as materials with a cement matrix
and a characteristic compressive
strength of 150 MPa–250 MPa. The
most common methodology to prepare
UHPFRC is cement + silica fume + very
low water to binder (w/b) ratio + fine
aggregate + superplasticiser + fibre [4].
Fibres are added to improve the ductility
of UHPFRC. Thanks to its extremely
excellent mechanical properties and
durability, UHPFRC has been considered
as the potential construction material
for the next generation infrastructures
[5]. The applications of UHPFRC are
growing all over the world, especially in
Europe, North America, Japan, Korea,
and Australia. It has been widely applied
for bridges, buildings, coastal structures,
structural repairing, military structures,
and so on [4]. However, the UHPFRC
material design guides or codes are not
fully developed right now, which inhibits
the wider application of UHPFRC in
infrastructure construction [4, 6].
With the increasing applications of
UHPFRC, there is a clear need in
developing material design methods
for UHPFRC. Conventionally, UHPFRC
is designed in the laboratory, with
series of experimental tests. However,
AFRICAN DESIGN MAGAZINE © | JULY 2018
51