Steel fiber & rebar reinforced concrete composite structure used in segmental joint

Researchers involved:

  • Gong Yifan  (PhD researcher)
  • Wouter De Corte (supervisor)
  • Luc Taerwe (supervisor)

Description:

In view of the local cracking and damage of the segmental joint structure, the appearance of fiber reinforced concrete provides a new way to solve the damage of the segmental joint structure in the construction stage. In terms of mechanism, the cracking of concrete can be attributed to the combination of the initial defects in concrete and the continuous expansion of micro-cracks under external loads, resulting in macro-cracks. The elastic modulus and tensile strength of the steel fibers are much higher than those of the concrete matrix are. At this time, the external load is mostly borne by the bond stress between the steel fibers and the concrete matrix, which prevents the expansion of the micro-cracks, reduces the width of the macro- cracks and shows excellent crack resistance. In addition, the steel fibers distribute in the concrete matrix evenly, as a result, the synergistic force between the steel fibers and the concrete reduces the stress concentration. However, the tensile side bearing capacity of steel fiber reinforced concrete is lower than that of reinforced concrete due to its high demand of pouring technology and large eccentricity bending, which makes the application of fiber reinforced concrete less. At present, reinforced concrete segment is still the mainstream in design and construction because the calculation theory of reinforced steel fiber reinforced concrete segment structure is not mature. Blindly conservative and excessive reinforcement increase the cost and hinder its further development. In summary, in order to promote the application of steel fiber reinforced concrete segments, it is necessary to carry out targeted new tests, build new models and methods, and establish more scientific, reasonable and reliable calculation methods and design theory of steel fiber reinforced concrete segments.

Gong Yifan

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