Abstract:
In conventional concrete pavement design methods the design parameters are determined
using linear elastic analysis. Concrete is subject to significant size effect and as a result linear
elastic design concepts, such as the modulus of rupture determined for a beam, have limited
reliability in the design of elements of different size and geometry. The objective of this paper is to
demonstrate that, in contrast to the modulus of rupture, fracture mechanics material parameters
can be used to accurately and precisely predict the flexural capacity of elements of a different
size and geometry. The experimental framework includes two high-performance fibre-reinforced
concrete mix designs, used to produce beams of different sizes tested in three-point bending
configuration, as well as centrally loaded round panels. The fracture energy of the material is
determined from the flexural beam tests. An adjusted tensile splitting test procedure is used
to determine the tensile strength. The flexural tests on the beams and panels are simulated
numerically using two finite element implementations of a cohesive crack approach. The
numerical simulation yields satisfactory prediction of the flexural behaviour of the beam and disk
specimens. It is concluded that using a fracture mechanics approach, the flexural behaviour of
structural elements of different size and/or geometry can be reliably predicted.
