Effect of Fly Ash on Compressive Strength, Drying Shrinkage, and Carbonation Depth of Mortar with Ferronickel-Slag Powder

Round 1

Reviewer 1 Report

The Portland cement manufacturing technology is a process having a lot of disadvantages, comprising consumption of big quantity of natural resources, very high energy consumption, significant environmental pollution including high emission of CO₂ resulting from the decarbonization of raw material. The significant energy consumption is due to a high temperature needed to run the clinker burning process. The Portland cement manufacturing requires the temperatures 1400-1500˚C. Limitations of the emission of CO₂, imposed by the European Union prompt to researches on innovative materials containing lower quantities of clinker. In this study, used ferronickel-slag powder and fly ash.

1. The introduction should be expanded to include existing research.
2. Which was the main focus of the research.
3. Moreover, the total content (91.5%) of the silica (SiO2 – 64.88%), aluminum dioxide (Al2O3 – 20.56%) and iron oxide (Fe2O3 – 6.06%) in the fly ashes and

moreover, the total content (54.56%) of the silica (SiO2 – 48.91%), aluminum dioxide (Al2O3 – 2.08%) and iron oxide (Fe2O3 – 3.57%) in the ferronickel slag powder.

4. What is their pozzolanic activity index.
5. What is the influence of the chemical composition on the properties of mortars.
6. Table 2. Mix proportions - what about the aggregate, no mortar composition without additive.
7. Figure 6. Drying shrinkage - not readable.
8. All test results should be compared to the mortar without additive.
9. No statistical calculations for compressive strength standard deviation, variation index.

Author Response

Thank you for your comments to the manuscript.

Authors have revised the manuscript as below in accordance with reviewer’s comments.

We would like to resubmit this paper, and we hope you will consider this paper as suitable for publication in your journal.

 

We are looking forward to your reply.

Thank you in advance.

Author Response File: Author Response.doc

Reviewer 2 Report

1. The paper has attempted to address the problem of ferronickel slag that is a troublesome byproduct, which has no enough chance for utilization as a raw material. It is an appreciable attempt.
2. The fundamental problem of the proposed paper is; the authors have erroneously used the word “mortar.” The authors have investigated a “paste” but not a “mortar.” Surprisingly, they have explained about the sand used in these experiments (lines 71-72), but sand is missing in the mix proportions, giving in the Table 2. This problem (including the title of the paper) should be solved before further reviewing.
3. The purpose of the research is a little ambiguous. Which kind of a problem the authors wanted to solve by using ferronickel slag and fly ash together? The issues of using ferronickel slag alone should be discussed by giving information from the previous literature.  
4. The readers may desire to know what will happen, if only cement (no ferronickel slag and fly ash) samples were made as the control experiment.
5. The argument on increasing flow with increasing ferronickel slag (lines 123-127) should be reconsidered. Generally, irregular particles of ferronickel slag should decrease the flow properties. Did the authors measure the Blaine specific area of fly ash? (I assume that Blaine of fly ash is very high). On the other hand, the flow values are within the allowable limit of error (120±5).  
6. The conclusions given are just observations. The readers may desire more concrete opinions such as, for instance, using ferronickel slag and fly ash together is better than using ferronickel slag alone.
7. Some spelling mistakes have been found (Ex. Line 76, 79 slag power→ slag powder).

Author Response

Thank you for your comments to the manuscript.

Authors have revised the manuscript as below in accordance with reviewer’s comments.

We would like to resubmit this paper, and we hope you will consider this paper as suitable for publication in your journal.

 

We are looking forward to your reply.

Thank you in advance.

Author Response File: Author Response.doc

Reviewer 3 Report

The authors investigated the fluidity, microhydration heat, compressive 15 strength, drying shrinkage, and carbonation characteristics of a ternary cement mortar including 16 ferronickel-slag powder and fly ash. Tests were conducted and conclusions were made about the compressive strength, shrinkage, etc. The results were also analyzed quantitatively. The reviewer feels that this research has some merits, but the analysis is not deep enough. Please explain why the Carbontation depth decreases first and then increases from FA20FN00 to FA00FN20. A recent article is suggested for your reference, Journal of Materials in Civil Engineering, volumn 32, issue 8, article number 04020194, 2020. Please revised Figure 6 with small points in the curves. Overall this work is interesting and can be considered for publication after revision.

Author Response

Thank you for your comments to the manuscript.

Authors have revised the manuscript as below in accordance with reviewer’s comments.

We would like to resubmit this paper, and we hope you will consider this paper as suitable for publication in your journal.

 

We are looking forward to your reply.

Thank you in advance.

Author Response File: Author Response.doc

Round 2

Reviewer 1 Report

The article has been corrected.

Reviewer 2 Report

Authors have sufficiently answered the reviewer’s comment.

One misspelling has been found.

Line 213: in general→ In general