Mesoscale Mechanical Analysis of Concrete Based on a 3D Random Aggregate Model

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Manuscript ID: coatings-3759882

Manuscript Title: Mesoscale Mechanical Analysis of Concrete Based on a 3D Random Aggregate Model

The following corrections are recorded:

1. While the authors have reviewed a substantial portion of the literature, they have not provided a detailed explanation of the findings from previous studies. Therefore, this aspect requires further elaboration.
2. Why were different types of aggregates not considered? Did the results obtained vary based on the type of aggregate used? Please explain.
3. The results of section 4.1 should be compared with the related literature.
4. Additional explanations should be added to improve the discussion of the results in Section 4.3, as the current explanations are not comprehensive.
5. Provide the limitations of the study at the end of the conclusions.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Table 1 provides a detailed summary of the concrete mix composition, including specific quantities of water, cement, and other constituents. However, the connection between these mix proportions and the parameters used in the 3D Random Aggregate Model should be clarified. It is important to explain how the physical characteristics of the experimental mix were translated into the model's input variables.

The description accompanying Figure 18a requires further elaboration. The simulation under uniaxial compression yielded an ultimate strength of 31.1 MPa, which corresponds closely to the experimental value of 33.8 MPa. The modeling assumptions, boundary conditions, and validation strategy should be clearly explained to support this comparison.

Although Figure 21 analyzes the effect of different aggregate sizes on mechanical performance, the actual shape of the aggregates used in the experimental program is not clearly stated. This information is essential to properly correlate the experimental results with the numerical model.

The conclusion should be enhanced by including key quantitative findings that reinforce the study’s outcomes and provide more definitive insights.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors presented a three-dimensional, three-phase mesoscale model including coarse aggregates, mortar and interfacial transition zone to study the compressive properties of concrete. Based on this mesoscale model, an efficient discrete element model (DEM) was developed to simulate the behavior of concrete under compression, including failure modes and stress-strain curves. The proposed mesoscale model demonstrates high reliability in analyzing the compressive properties of concrete. The paper demonstrates a high degree of novelty - the proposed algorithm for generating 3D aggregates taking into account the distribution of the maximum radius significantly reduces the computational costs; the work combines several geometric approaches into a single working scheme; the developed model is verified for compliance with actual experimental data. The toolkit of the model can be useful in industrial modeling and structural mechanics.

Comments and recommendations:

1. Section 4.1 (line 381) states that additives were used in the production of concrete samples, but the text does not specify what additives these were or their quantities.

2. Lines 387-388 – state “The mass densities of the cement and water are 340 kg/m³ and 178 kg/m³, respectively.” Perhaps this means “contents of cement and water,” since cement and water have another density values.

3. Lines 433-444 do not indicate what composition of the concrete mix was used to produce the samples. Was it the same composition as indicated in Table 1?

4. Lines 435 and 439 – the number of the Table referenced by the authors (Table 2) should be indicated.

5. The conclusions should be supplemented by an indication of the limitations of the model, in particular when modeling coarse-grained concrete with fibers or additional phases.

6. The figures do not always have a scale and numerical captions (Figures 17, 19, 20, 22, 23), in some cases this does not significantly affect the perception of information. However, in Figure 18 b it would be useful to add a scale or numerical axes.

In general, the article is a high-quality scientific study with a relevant topic, an innovative approach and good theoretical and experimental justification. It is recommended for publication after making corrections and clarifications in accordance with the comments made.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

all comments were addressed.