Investigations into the relationship between deflection and crack mouth opening displacement of SFRC beam

Currently there are only few research results for predicting the relationship between deflection and the crack mouth opening displacement (CMOD) of steel fibre reinforced concrete (SFRC) beams. A series of bending beam tests on SFRC, with different fibre contents and fibre types have been carried out. Based on the experimental results a model for predicting the relation between the deflection and CMOD of SFRC has been established. This model relies on the load–deflection relation and the load–CMOD relation of bending beam. A well agreement has been found between the suggested mode and the test results of other research. The results of this mode indicate that the load–deflection diagram is very similar to that of the load–CMOD diagram, and there is a linear relation between the mid-span deflection and CMOD of SFRC.

Research highlights
► We analyze the experimental results of SFRC beam with different fibre contents.
► We compare the load – deflection relation and the load–CMOD relation of bending beams.
► The residual load of beams at large deflection and CMOD increased with the increasing of steel fibre content and fibre length.
► A model for predicting of the relationship between deflection and CMOD of SFRC beam is established with sufficient reliability.