Adapted Schmidt Hardness Testing on Large Rock Samples—Kanfanar-South Quarry Case Study
Round 1
Reviewer 1 Report
The paper proposes a Schmidt hardness as a simple indicator of the hardness in commercial blocks instead of visual observation. The authors prepare Schmidt hardness test on commercial blocks as bulk and scatter methods, and have studied the influence of the type of machine used to cut the tested surfaces. The overall writing quality of the paper is good. Nevertheless, I have some miner comments that should be considered.
Major comments:
1. My main criticism is the novelty of the work. I don’t see enough novelty in the paper to make it published. The Schmidt test is well-known and the study has not brought anything special to that. Its just scaling up the test. Maybe, it would be more meaningful to consider this paper as a technical note.
Minor comments:
1. Please double check the paper for the typos. i.g. In page 1 “smidt hardness”
2. All of the abbreviations should be defined at least once in the paper. Like ‘UCS’ page 2.
3. Maybe its good the add a figure to the discerption presented in section 2
4. In paragraph 1 of the section 3 the authors have mentioned figure 4b wrongly.
5. Authors have brought a graph in figure 7, but they did not discuss about the reasons of these differences. They should reconsider the graphs and make a discussion about them to improve the level of their research.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Introduction - please prepare a table with comparative results from the literature, there is no detailed research methodology described, there are no comparative results taking into account the statistical hypothesis, there is no numerical model with the described indicators, conclusions - all results should be completed.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
This is good work, but the text needs to be tightened and streamlined. Succinctly present just the facts and novelty, do not elaborate too much on the history of testing. Remove some of the figures, especially with the engineer conducting the testing. Only keep the figures that are of immediate relevance to the thesis of the paper.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
The article Adapted Schmidt hardness testing on large rock samples describes Schmidt hammer testing of limestone rock blocks from the Kanfanar-South quarry in Croatia. The work is concise and understandable, although it has some shortcomings.
1. The aim of the research is not clearly formulated. The purpose described in paragraphs 88-92 is somewhat enigmatic. Please outline the purpose of your research in more detail.
2. The authors collected a lot of scientific articles, but did not mention several hardness testing methods (including Vickers test). Examples:
Godyń, K.; Kožušníková, A. Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland. Energies 2019, 12, 1756. https://doi.org/10.3390/en12091756;
Mukherjee, A.K.; Alam, M.M.; Ghose, S. Microhardness Characteristics of Indian Coal and Lignite. Fuel 1989, 68, 670–674;
Oliver, W.C.; Pharr, G.M. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res. 1992, 7, 1564–1583
et al.
3. Chapter 2.1 - the authors cite a number of information of a broadly understood geological nature, but do not specify whether these are the results of the authors' own research or are based on literature. Please complete in.
4. chapter 2.2. The authors describe some elements of the Schmidt method, but they do not explain the principle of operation, and they do not show the equipment in the picture. Please complete this information, preferably with a photo of the equipment used and the test procedure (the device is practically invisible in fig.4).
5. It is debatable whether the method is less energy-intensive and introduces more sustainable production. The authors describe this in paragraphs 285-290. In paragraphs 254-256, the authors write that the test surface should be sanded, so the energy consumption must also increase to properly test the samples. Please think about it.
The work requires some corrections and additions, but if the authors make corrections in accordance with the reviewer's comments, the work may be published in the journal Sustainability
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Thanks for authors' reply.
The overall quality of the paper is fairly good. However, i still recommend it to be published in the form of technical note due to the lack of novelty.
regards.
Author Response
Response to Reviewer 1 Comments
Point 1: The overall quality of the paper is fairly good. However, i still recommend it to be published in the form of technical note due to the lack of novelty."
Response 1:
Dear reviewer
Despite our different views on the nature of the manuscript, all authors are grateful for your efforts and suggestions to improve this paper. However, since there are no suggestions on how to further improve the paper, we can only humbly ask that the following arguments be considered.
The authors did not write a brief article (technical note) in which they attempted to describe a change to an existing technique or procedure.
The authors state that the research paper is based on original research. The authors spent considerable time collecting and analyzing raw data as part of a case study of the Kanfanar-South quarry. At 6227 words, the article is almost twice as long as a technical note.
This paper emphasizes the novelty because commercial blocks of natural stone have never been investigated for Schmidt hardness and are not described in the existing literature. The authors are convinced that the article's format must be published first. A technical note should be issued after additional testing, possibly in multiple quarries.
I wish you all the best.
Assoc. prof. Zlatko Briševac
Reviewer 2 Report
Dear Authors, There is still no such analytical method to compare experimental, theoretical and numerical results. In addition, the results need to be expanded, descriptions are missing.
Author Response
Response to Reviewer 2 Comments
Point 1: Dear Authors, There is still no such analytical method to compare experimental, theoretical and numerical results. In addition, the results need to be expanded, descriptions are missing."
Response 1: This remark is taken seriously by the authors, but it is extremely difficult to understand what is specifically requested from just two sentences. The comments are too general and unclear. As a result, they politely and humbly request detailed instructions from reviewer 2. In what sense is the analysis method incomplete, and where should it be finished?
What do you mean by "expanding results" exactly? Where in the text should the results be expanded and described? The authors of this manuscript are also reviewers for prestigious scientific journals, so they understand and believe that a good and acceptable review includes detailed suggestions for the authors and not only, and they humbly hope that reviewer 2 will help them in this context.
With all due respect,
Assoc. prof. Zlatko Briševac
Round 3
Reviewer 2 Report
Dear Authors, Please complete this numerical model, together with the comparison of experimental and theoretical analysis and numerical in the table.
Author Response
Response to Reviewer 2 Comments
Point 1: Dear Authors, There is still no such analytical method to compare experimental, theoretical and numerical results. In addition, the results need to be expanded, descriptions are missing."
Response 1: The authors are grateful to the reviewer for his time and effort spent on improving this paper and making it worthy of publication in Sustainability. The comparison is described in lines 324 to 334 and table 7 is added. The results were expanded in lines 271 to 278. Two tables (4 and 5) describing test results by layers were added.
With all due respect,
Assoc. prof. Zlatko Briševac, corresponding author
