Flexural Behavior of Steel Fiber Reinforced Concrete Beams: Probabilistic Numerical Modeling and Sensitivity Analysis

Round 1

Reviewer 1 Report

This paper combines global variance-based sensitivity analysis with a finite element model of SFRC beam under four-point loading to identify material properties whose uncertainty contributes the most to the uncertainty in the flexural behaviour of a SFRC beam.

Line 273: “For these model inputs, it is assumed that the CoV of plain concrete can be used for SFRC.” This sentence should be justified so that it has scientific rigor.

Figure 10: The results of the collapse displacements obtained from the numerical model are not in good agreement with experimental result maybe because the compressive constitutive equation used for the concrete is too simple. If the constitutive equation had a post-peak descending branch the stress in the reinforcements would increase, consequently the curvature and the mid span displacement. Maybe, another definition of collapse should be used, for example, when the borne load decreased 15%. This is used by many authors to calculate de ductility.  

Line 358: “Ductility of the beam specimens is calculated as the ratio between the collapse and the yield displacement.” There are many ways to compute de ductility. Most of them requires the load overtakes the peak and descends. Authors should justify why they use this way to compute the ductility and cite the followed reference.

Figure 11: The comment on Figure 10 also applied to this figure.

Figures 14-20: Abscissa’s axis captions should be in horizontal form, not in vertical.

Some changes need to be performed in the finite element model. The agreement between displacements in failure state is not good enough. Therefore, the model cannot reproduce the reality under the current form.

Author Response

The authors would like to thank the reviewer for the comments and suggestions for improvements. They have been thoroughly considered before the manuscript was changed, as described in the file we have uploaded here.

Author Response File: Author Response.pdf

Reviewer 2 Report

The title and the content of the manuscript sound very interesting to the readers. However, its English needs improvement, for example, in the introduction, line 3: second“reinforced” should be removed. And there are some grammatical errors as well. Moreover, the section relevance to the FEM is not presented in detail. All in all, my recommendation is to accept the manuscript after a minor refinement. 

Author Response

The authors would like to thank the reviewer for the comments and suggestions for improvements. They have been thoroughly considered before the manuscript was changed, as described in the file we have uploaded here.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have not made the suggested changes of the review. The conservative estimation of collapse displacement invalidates the results. For this reason the paper is not suitable for the publication.