Optimization of Coarse Aggregate Size Distribution for Preplaced Aggregate Cement Paste Coating Concrete

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

While the abstract gives a concise summary of the research and findings, it can enhance some quantitative results, such as the given or the percentage improvement in the efficiency of a cement or compressive strength. The novel casting method is well expounded in itself but could probably be more potent by presenting upfront the most significant findings.

 

The methodology is fairly detailed but needs adding more particular calibration or validation information for the test equipment to improve reproducibility. A more specific justification is required concerning aggregate proportions and W/C ratios. In addition, the reason for choosing certain ranges must support this.

 

Figures such as 3 and 4 clearly illustrate packing density, but the readers, in fact, would want to see how these results associate with real-life issues. The study may also wish to discuss how its results stack up against prior studies or industry benchmarks to put gains in cement efficiency and strength in context. Figures 6-17 are very informative, yet would benefit from trend lines or statistical significance markers to add interpretability.

 

The manuscript is otherwise well written, but it has some small grammatical errors (e.g., "the groutability of is inversely related to the strength" in the conclusion). 

 

These references are quite comprehensive; however, more literature published in 2023-2024 in this area would provide a more substantial basis for the context within which the study sits.

 

Picture resolution of SEM images should be made better for microstructural differences to be clearly visualized.

Author Response

Thank you for the review effort and constructive suggestion. Please see the attached response to reviewer's comment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

See noted in the attached file

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Moderate English editing is required.

Author Response

Thank you for the review effort and constructive suggestion. Please see the attached response to reviewer's comment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

• How does the optimal packing density of aggregates influence both the mechanical strength and the groutability of CPCPA concrete, and what compromises must be made in practical applications? (Lines 177–198, 399–420)

• What is the impact of aggregate particle size gradation on the interfacial transition zone, and how does this affect long-term durability? (Lines 326–341)

• How does the microstructure of the cement paste, as observed under SEM, explain variations in mechanical properties with different W/C ratios? (Lines 342–348)

• What mechanisms lead to the inverse relationship between groutability and compressive strength in CPCPA concrete, and how can this balance be optimized in design? (Lines 14–18, 273–299)

• To what extent does the presence of cracks in the interfacial transition zone, as observed in SEM analysis, correlate with reduced mechanical performance? (Lines 331–337)

• How do variations in W/C ratio influence the development of C-S-H gel and its contribution to the bonding within the interfacial transition zone? (Lines 363–371)

• What role does aggregate vibration during molding play in achieving maximum packing density, and how does this affect the flow of cement paste during grouting? (Lines 183–193, 247–260)

• How does the porosity distribution, measured through mercury intrusion porosimetry, relate to the resistance of CPCPA concrete against environmental degradation? (Lines 352–360)

• What are the theoretical limitations of the modified A-A particle size distribution model used in this study, and how might it be further refined for modern concrete applications? (Lines 206–220)

• Why does the strength and efficiency of CPCPA concrete vary so significantly with minor adjustments in small particle ratio, and what are the underlying microstructural explanations? (Lines 278–311)

• How does the balance between aggregate packing density and cement paste flowability contribute to achieving optimal cement efficiency, and how can this principle be scaled for industrial applications? (Lines 399–421)

• What are the potential implications of using preplaced fiber concrete under pressure in combination with CPCPA techniques, and what research gaps remain in this area? (Lines 378–389)

• Thank you for quoting this article which is related to your work.   https://doi.org/10.1016/j.powtec.2022.117583

Comments on the Quality of English Language

Some grammatical errors  

Author Response

Thank you for the review effort and constructive suggestion. Please see the attached response to reviewer's comment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The paper can be accepted

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for addressing most of comments.

Reviewer 3 Report

Comments and Suggestions for Authors

the authors have taken all comments into account, the article is publishable as is