Study on the Effect of Amorphous Silica from Waste Granite Powder on the Strength Development of Cement-Treated Clay for Soft Ground Improvement
Round 1
Reviewer 1 Report
The author just needs to change the title to mention the fact that this paper has a contribution to geotechnical engineering
Author Response
The author just needs to change the title to mention the fact that this paper has a contribution to geotechnical engineering
Thank you so much for reviewing our manuscripts and for the kind suggestions to improve our manuscript.
We have intensively checked the grammar of the paper, and an English editing company was contacted for this purpose.
The title was also changed to “Study on the effect of amorphous silica from waste granite powder on the strength development of cement-treated clay for soft ground improvement” in order to show its applicability to geotechnical engineering.
Reviewer 2 Report
See as the attachment.
Comments for author File: 
Comments.pdf
Author Response
The efforts of the authors are highly appreciated. Find below suggestions to improve the manuscript:
Thank you so much for reviewing our manuscripts and for the kind suggestions to improve our manuscript. We have addressed most of the comments and kindly request to address the rest of them in the future.
State clearly the aim and objectives of this study as well as significance in introduction section.
Besides mentioning the research gaps in each paragraph, we have clearly stated the novelty of this manuscript in lines 100-109 as follows:
Understanding the mechanisms of UCS development should help inform the geotechnical engineers of the effective reuse of waste stone powder for soil improvement, which improves the environmental sustainability of the construction industry. Therefore, the present study explained the mechanisms resulting in UCS differences in cement-treated clay containing stone powder of various particle sizes. Physical parameters, namely liquid limit, and flow value, of cement-treated clay; the chemical composition of stone powder, including its amorphous silica concentration; pozzolanic reactivity, and particle size variation, were determined. The thermal parameters such as chemically bound water and calcium hydroxide content were also conducted to confirm the chemical reactions between cement-clay pastes and stone powder.
Beside investigated properties, please check effect of treatment on extra mechanical properties and durability properties of the composite.
Thank you so much for this observation. The objective of this paper was to explain the reasons for the UCS improvement and variation caused by the different particles sizes of stone powder which was initially reported in our paper cited as [26]. The significant finding in the mentioned paper was the variation of UCS of cement-treated clay with the particle size of stone powder. Our current paper addresses unanswered questions about the strength variations caused by the differences in amorphous silica concentration that varies with particle size. However, we are considering investigating the composites' different mechanical and durability properties in our upcoming research.
[26] J. Nakayenga, A. A. Cikmit, T. Tsuchida, and T. Hata, “Influence of stone powder content and particle size on the strength of cement-treated clay,” Constr. Build. Mater., vol. 305, no. February, p. 124710, 2021, doi: 10.1016/j.conbuildmat.2021.124710.
Please cite the following related papers on clay-granite and treatment:
Li L, Xuan D, Sojobi AO, Liu S, Poon CS. Efficiencies of carbonation and nano silica treatment methods in enhancing the performance of recycled aggregate concrete. Construction and Building Materials 308 (2021) 1-10
It was challenging to find a suitable way of citing this paper; however, we are considering citing it in our future research.
AO Sojobi, TF Awolusi, GB Aina, OL Oke, M Oladokun, DO Oguntayo. Ternary and quaternary blends as partial replacement of cement to produce hollow sandcrete blocks. Heliyon 7 (2021) 1-14
This paper below has been cited in line 42
[12] A. O. Sojobi, T. F. Awolusi, G. B. Aina, O. L. Oke, M. Oladokun, and D. O. Oguntayo, “Heliyon Ternary and quaternary blends as partial replacement of cement to produce hollow sandcrete blocks,” Heliyon, vol. 7, no. January, p. e07227, 2021, doi: 10.1016/j.heliyon.2021.e07227.
Also, please check if it the treatment has effect on elevated temperature resistance of the composite and cite related paper below:
Awolusi TF, Sojobi AO, Afolayan JO. SDA and laterite applications in concrete: Prospects and effects of elevated temperature. Cogent Engineering 4, (2017), 1-20
Since we are considering researching the durability of the proposed cement-treated clay stone powder composites, we kindly request to evaluate these parameters in our upcoming research.
Kindly recommend the best granite particle size considering investigated properties. The best granite particle size can be obtained using linear weighted optimization approach proposed by authors below and cite them:
- Sojobi, K. M. Liew. Flexural behaviour and efficiency of CFRP-laminate reinforced recycled concrete beams: Optimization using linear weighted sum method. Composite Structures (2021), 260, 1-16
Thank you so much for your kind suggestion. Considering that we only conducted the UCS test as the mechanical property at this time, we are unable to comprehensively use the linear weighted sum method to suggest the best granite particle size. We, however, are hopeful that we shall be able to use the recommended method when we conduct other mechanical properties in our future research.
From our previous manuscript cited as [26], we suggested particle size <20 µm and <1–106 µm as the most particle size for improvement in cement-treated clay UCS based on their ability to improve strength and also reduce the interfacial transition zone (ITZ) between the clay-cement paste and stone powder particles. Hence we have added the statement below to lines 324-329 in section 3.2.
Stone powder of sizes <20 µm and <1–106 µm, used in cases 3 and 2 respectively, is suggested as the most effective particle size for improvement in cement-treated clay UCS [26]. Therefore, to decongest the charts and clearly present the benefits of using stone powder and variations in composites due to stone powder particle size, only cases 1,2,3 ,1c, 2c and 3c have been presented in Figures 1 and 2 and herein discussed. The UCS development of all the test cases can be found in Figures A3 and A4 in Appendix A.
[26] J. Nakayenga, A. A. Cikmit, T. Tsuchida, and T. Hata, “Influence of stone powder content and particle size on the strength of cement-treated clay,” Constr. Build. Mater., vol. 305, no. February, p. 124710, 2021, doi: 10.1016/j.conbuildmat.2021.124710.
State the implications of your main findings for policy, research and industry in the conclusion section.
Thank you very much for your insightful suggestion. The statement below was added to lines 523-527
This implies that granite quarrying industries in Japan can supply the silt size particles of stone powder to geotechnical engineering projects involving the improvement of dredged clays using cement. Hence, the Basic act for Establishing a Sound Material-Cycle Society in Japan should be revised to incorporate the reuse of granite stone powder, which substantially contributes to meeting Goal 12 of the Sustainable Development Goals (SDGs).
Please include picture of materials and important equipment used.
The photographs have been added to Appendix A as Figure A1 and A2
Reviewer 3 Report
Dear authors, the submitted manuscript is really well written and elaborated and I believe it can be accepted for publication in Journal as the following comments will be addressed in its revision.
i) The Introduction section is excessively long. It might be reduced and the novelty of the manuscript must be clearly stated. Please, revise this part of the manuscript.
ii) It would better present in Figures 1 and 2 the measured UCS curves for all examined materials. Please, complete or comment.
iii) There are more precise methods for the evaluation of pozzolanic activity, such as Frattini and Chapelle tests. It is not clear, why such highly popular chemical methods were not applied. The conductivity method in such low reactive materials is from my point of view on the edge of its applicability. What do you think? Please, comment.
iv) The compressive strength data is usually presented in MPA. Please, revise.
Author Response
Dear authors, the submitted manuscript is really well written and elaborated and I believe it can be accepted for publication in Journal as the following comments will be addressed in its revision.
Thank you so much for reviewing our manuscripts and for the kind suggestions you have offered to improve our manuscript. We have addressed most of the comments and commented on a few that we were unable to handle. We hope that the revisions are appealing enough.
i) The Introduction section is excessively long. It might be reduced and the novelty of the manuscript must be clearly stated. Please, revise this part of the manuscript.
We tried to reduce the introduction section, to address both your request and reviewer 2’s request to add content to the manuscript. Unfortunately, we could only reduce it to 1058 words because the further reduction would lead to the loss of meaningful content. In this section, we need to explain the need to reuse stone powder, available reusability options in the concrete and geotechnical engineering field, explore the known mechanisms of strength development of cement-treated clay, and the possible interactions of stone powder and cement’s hydration products.
However, besides mentioning the research gaps in each paragraph, we have clearly stated the novelty of this manuscript in lines 100-109 as follows:
Understanding the mechanisms of UCS development should help inform the geotechnical engineers of the effective reuse of waste stone powder for soil improvement, which improves the environmental sustainability of the construction industry. Therefore, the present study explained the mechanisms resulting in UCS differences in cement-treated clay containing stone powder of various particle sizes. Physical parameters, namely liquid limit, and flow value, of cement-treated clay; the chemical composition of stone powder, including its amorphous silica concentration; pozzolanic reactivity, and particle size variation, were determined. The thermal parameters such as chemically bound water and calcium hydroxide content were also conducted to confirm the chemical reactions between cement-clay pastes and stone powder.
ii) It would better present in Figures 1 and 2 the measured UCS curves for all examined materials. Please, complete or comment.
Our main intention was to express the benefits of reusing stone powder, including the increment in UCS of the composites and reduction increment quantities while still displaying the variations in strength with the particle size of stone powder. This can also be communicated using all 7 test cases, but representing them in the same line graph complicates the chart and makes it difficult to read. Cases 1,2,3, and 1c, 2c, and 3c can easily communicate the message, so we chose to represent only those. However, we have opted to include Figures A3 and A4 in the appendix to represent all the cases. And the following statement has been added to Line 324-329 in section 3.2.
Stone powder of sizes <20 µm and <1–106 µm, used in cases 3 and 2 respectively, is suggested as the most effective particle size for improvement in cement-treated clay UCS [26]. Therefore, to decongest the charts and clearly present the benefits of using stone powder and variations in composites due to stone powder particle size, only cases 1,2,3 ,1c, 2c and 3c have been presented in Figures 1 and 2 and herein discussed. The UCS development of all the test cases can be found in Figures A3 and A4 in Appendix A.
[26] J. Nakayenga, A. A. Cikmit, T. Tsuchida, and T. Hata, “Influence of stone powder content and particle size on the strength of cement-treated clay,” Constr. Build. Mater., vol. 305, no. February, p. 124710, 2021, doi: 10.1016/j.conbuildmat.2021.124710.
iii) There are more precise methods for the evaluation of pozzolanic activity, such as Frattini and Chapelle tests. It is not clear, why such highly popular chemical methods were not applied. The conductivity method in such low reactive materials is from my point of view on the edge of its applicability. What do you think? Please, comment.
We chose the method because of its rapid nature, ease of operation and availability, its popularity among other researchers. The statement below was added to lines 242-245 in section 2.4.5.
Although this is an indirect method for measuring pozzolanic reactivity, it has been popularly used [42]–[45] and was chosen for its availability and ease of operation. Its robustness was checked by the direct method of TG-DTA.
[42] S. Velázquez, J. M. Monzó, M. V. Borrachero, and J. Payá, “Assessment of pozzolanic activity using methods based on the measurement of electrical conductivity of suspensions of portland cement and pozzolan,” Materials (Basel)., vol. 7, no. 11, pp. 7533–7547, 2014, doi: 10.3390/ma7117533.
[43] F. A. Cedrim, G. A. de Oliveira e Silva, T. A. Santos, and D. V. Ribeiro, “Pozzolanicity evaluation of mineral additions by electrical conductivity measurements,” Mater. Sci. Forum, vol. 881 MSF, no. November, pp. 239–244, 2017, doi: 10.4028/www.scientific.net/MSF.881.239.
[44] M. Luxàn, P, F. Madruga, and J. Saavedra, “Rapid Evaluation of Pozzolanic Activity of Natural Products by Conductivity Measurement,” Cem. Concr. Res., vol. 19, pp. 63–68, 1989.
[45] S. Maximilien, J. Péra, and M. Chabannet, “Study of the Reactivity of Clinkers,” Cem. Concr. Res., vol. 27, no. 1, pp. 63–73, 1997.
iv) The compressive strength data is usually presented in MPA. Please, revise
The units have been changed to MPa.
Round 2
Reviewer 2 Report
Well done for improvement of the manuscript.
