Effect of Fiber Types and Dosages on the Properties of Modified Aluminum Dross–Coal Gangue-Based Foam Filling Materials
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors,
The article examines the use of polypropylene and polyacrylonitrile fibers in cementitious filling materials made from modified aluminum foam and coal gangue. The findings indicate that incorporating fibers significantly enhanced compressive strength and delayed crack formation. Additionally, the study identified rheological challenges caused by the fibers, including reduced fluidity and increased viscosity, with these effects being less pronounced for longer fibers.
To enhance the article, the following recommendations are proposed:
-The authors should clearly state that the results are confined to the specific fibers and experimental conditions studied, indicating that the findings are not yet suitable for direct industrial application;
-The study evaluates multiple variables simultaneously (fiber type, length, amount, and material composition), which complicates the interpretation of the results. An isolated analysis of each variable should be provided;
-Include a detailed comparison of the results with those of conventional filling materials or other reinforcement methods. Additionally, provide a cost-benefit analysis of using the waste material to promote its large-scale adoption;
-The conclusions should emphasize the need for durability studies to evaluate the material’s resistance to thermal cycles, corrosion, and other environmental conditions.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsMinerals-3352010: Effect of fiber types and dosages on the properties of modified aluminum dross-coal gangue-based foam filling materials
General comments
The manuscript reports the effect of two different types of fibers on the mechanical properties of a foamed cementitious material. Fiber content and fiber length are varied for the two fiber types. A wide range of parameters have been used to compare performance.
The manuscript has a significant number of concerns. Firstly, the description of some methodological steps need enhancement to add clarity. For example, why was 48hrs adopted for curing before demoulding as opposed of the more common 24hrs?
Some illustrations are not helpful, and can be obviated altogether, such as Figure 11. Also, some figure captions are too brief and full and detailed figure captions describing what is presented are recommended for all figures. In other instances, figures could be made sharper, such as Figure 2. The authors have not effectively used different data markers and trend lines to help the reader differentiate the series in illustrations, as explained in Figures 3 and 4 in the annotated copy attached. Scales in illustrations are not carefully selected. In Figures 6 and 7 for example, a common y-axis would make comparisons easier.
Some arguments by the author do not conform with known facts. For example, the argument that high silica content can render a material particularly suitable for use as aggregates in construction materials (Section 2.1.3) appear to suggest that the authors are oblivious or unaware of the fact that high silica content in aggregates is also associated with adverse alkali-silica reaction. This fact is not mentioned, considered or factored when making this statement on Coal Gangue (CG) high silica content. In addition, the physical properties of the CG are not presented to the reader.
The conclusions bullet points are deemed weak and need restructuring and strengthening. Some conclusion bullet points read like reporting of results.
Overall, there is a general lack of succinctness in reporting, and some editorial errors could have been avoided. Chemical formulae for example are presented without using subscripts as seen in Tables 1 and 3 among other places. Figure 10 for example is presented before its introduction to the reader in the text. It is customary in publishing etiquette to firstly introduce an illustration in the text before presenting it to the reader.
Other confusing statements include in Section 2.2, where the authors argue that CFB containing 10% foaming agent was added to modified aluminum dross. They then state that the modified aluminum dross served as the foaming agent. This is confusing. It is like stating that A + B = B where Foaming agent + Aluminium dross = Aluminum dross. If aluminum dross served as the foaming agent, why was a foaming agent needed? For these reasons, there is need to edit lines 199-204 where this matter is dealt with, to make this matter of foaming agent clearer.
In summary, there are far too many issues with the manuscript. A major revision will be needed to enhance the quality of the manuscript to the level deemed commensurate with refereed journal publications. It is not possible to narrate all the adverse issues observed. An annotated copy is attached to highlight some of the areas where the said issues were observed.
Special comments
1. Section 2.1.1 – Table 2 shows elemental compositions and not oxide compositions. In this regard, it is incorrect to say that Table 2 shows the amounts of silica (SiO2). Silica is instead shown Table 1
2. Section 2.1.3 The market described as “environmental protection and building materials market” is unclear. Which market is this? This needs more clarity. Are these two sectors/markets (Environment and building materials) or one combined sector/market?
3. Section 2.1.3. It is recommended that the authors make a statement regarding the risk to alkali-silica reactions associated with aggregates with high or reactive silica content.
4. Section 2.1.4. It is appropriate at this stage to state/mention to the reader the microscopic differences between the two fibre types, as later seen in SEM micrographs.
5. Section 2.2. It is helpful to the reader to know at this stage the main aim of calcining AD with quicklime.
6. Figure 2. This illustration would need enhancement if at all possible. The lines could be sharper, text made more eligible, and explanation of difficult terms in the legend such as “yobs”, Rwp and other terms are among other improvements.
7. Table 6. It is always common to name/start the control mix, before naming/presenting the other trial mixes.
8. Section 2.3.5. Equation 1. It is customary to define all the parameters used in an equation, and not selectively defining some and leaving the others undefined.
9. Figures 3 and 4. The annotated copy shows suggestions on how to make differentiation of trendlines much easier to the reader. Also, all figure cations could be more detailed to provide more information about the different trendlines presented in the figure.
10. Figures 6 and 7. A common scale of 10 for the y-axis as done for figure 7(a) could make comparisons easier.
11. Figure 10 – should introduced in the text before representation to the reader.
12. Figure 11 – not deemed helpful to the reader at all.
13. Figure 13 – seriously needs a detailed caption.
14. Conclusions. It is recommended that the fragmented general comments be combined into one initial summary, followed by numbered or bulleted strong, clear, and brief conclusive statements.
Comments for author File: Comments.pdf
Average. Need improvements. See comments to authors
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsSome comments can be considered significant
Comments for author File: Comments.pdf
Generally, the English language and structure of the manuscript must be checked and improved.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsThe revised version addresses all comments, and the paper has been accepted in the given form.
