Investigation onmechanical property adjustment of multi-scale hybrid fiber-reinforced concrete

Abstract

In order to avoid the tunneling disasters in the adverse geology, the ultra-high performance concrete needs to be used for control the deformation. As a random multiphase material, concrete is mostly heterogeneous and heterogeneous, and its characteristics are complex. So the relevant test cycle is long and the cost is high. In order to know the required mechanical properties of the ultra-high performance concrete, the advanced research can be carried out by the finite element method. The fiber-reinforced concrete model was established to study how the multi-scale hybrid fiber-reinforced concrete has been enhanced by the finite element method. The concrete is considered as the elastic-plastic constitutive relationship, but the fibers in the concrete follow the elastic constitutive relationship. Eight-node hexahedral reduced integral elements are adopted for both matrix and fiber. The reliability and validity of the fiber-reinforced ultra-high performance concrete by the finite element method was verified by the experiment. It can be used to predict the mechanical properties of concrete with different fiber characteristics, but unable to be used to predict more complex behaviors such as damage and fracture. The results indicate that the compressive strength and the flexural strength of concrete with a fiber volume content of 1.0% are larger than other 6 different fiber volume content, the beam axially undergoes plastic deformation is the largest of the seven, and the fiber concrete numerical model can better simulate the static mechanical properties and the failure mechanism of fiber fibers when the fiber volume content is 0.1%, and the fiber length is 15 mm. This study can provide a reasonable and effective reference for the actual engineering.