Water/Cement/Bentonite Ratio Selection Method for Artificial Groundwater Barriers Made of Cutoff Walls
Round 1
Reviewer 1 Report
Water/Cement/Bentonite Ratio Selection Method for Artificial Groundwater Barriers Made of Cutoff Walls
ID: water-1526897
Comments Comments and Suggestions for Authors
A brief summary
The article describes the tests of bentonite mixture parameters. The basic composition of the initial mixture consisted of three components: water + cement + bentonite (W + C + B), which gave 100% of the mass. A triple diagram (WCB) was used to present the relationships of components. The ternary diagram is commonly used in land classification. Sand was added to the mixture in proportion only to the sum of the weight of cement and bentonite S: (C + B). The final mixture was obtained, consisting of the four main components: water + cement + bentonite + sand (W + C + B + S). A triple diagram (WCB) was also used to analyze the parameters (WCBS).
Broad comments
The procedure of determining the composition of the mixture and the research methodology is correct. In the opinion of the Reviewer, the triple diagram (WCB) cannot be used for the analysis of a mixture consisting of 4 main components. These were the basic ingredients of the final mixture. The mass of each component was greater than 5% of the total mass of the final mixture. This is a methodological error in compiling the research results. Sections: 3. Test results, 4. Discussion, 5. Conclusions should be improved.
Specific comments
(R.24) 1. Introduction.
(R.45-46) Comment
An important feature of the bentonite mixture is its contamination with the soil material in which the barrier is made.
It should be corrected.
Did the Authors take into account the susceptibility of the tested mixtures to contamination in the selection of the water / cement / bentonite ratio?
(R.69) 2. Preparation of samples
- 72-73. Comment.
On lines 50-53, the mass composition of the mixture is indicated, percentage of cement + percentage of bentonite + percentage of water = 1. For the three main components of the mixture, a ternary diagram was used using their mass percentages. Lines 72-73 indicate that sand was added to the mix 1: 1 based on the sum of the mass of cement plus the mass of bentonite. The sand increases the mass of the sample in 12 classes from 50% to 27% (the sum of cement plus bentonite). With the proportion of bentonite 25% plus cement 25%, sand in the proportion 1: 1 to the sum of these components is an additive to the mixture (50%), not an admixture (<5%). When sand was added, a sample of non-homogeneous variables was obtained. The addition of screech loads only the cement variable axis and the bentonite variable axis, and not the water variable axis. This interferes with the weight percentage of the total sample. At this point, the mix is 4 ingredients, not three. So we have a multiple analysis with four independent variables. In the opinion of the Reviewer, the triple diagram cannot be used for the analysis of 4 independent variables, as the whole does not constitute 1 (100%). The sum of mass percentage of cement + percentage of bentonite + percentage of water + percentage of sand is not equal to 1 (100%). The starting mixture (WCB) became the final mixture (WCBS) when sand was added. Physically, it is still one mixture. Statistically, it is the final mixture in which the percentage of ingredients is different than in the initial mixture. For example; Row 1 in Table 3, for final mixture (WCBS); W33.3% + C16.67% + B16.67% + S33.33% = 100%.
It must be corrected.
Section 3. Test results should be improved.
(R.101) . 3. Test results
(R.127) Figure 4. Viscosity variation of the fresh mixtures and marks of segregated sand samples.
Comment.
Figure 4 shows that the problem of sand segregation in the selection of the mixture composition is very important. The tested samples have 4 variables. Chart type for three-variable sum of 1 or (100%) analyzes.
It must be corrected.
Please change the analysis of the obtained results.
(R.134-135) Figure 5. Axial compressive strength.
Comment.
The tested samples have 4 variables. Chart type for three-variable sum of 1 or (100%) analyzes.
It must be corrected.
Please change the analysis of the obtained results.
(R.140-141) Figure 7. Permeability.
Comment.
Chart type for three-variable sum of 1 or (100%) analyzes. The tested samples have 4 variables.
It must be corrected.
Please change the analysis of the obtained results.
(R.144) . Table 3. Test data table
Comment.
Sand is not listed in table 3.
It must be corrected.
Table 1 should contain data on the full final resultant mixture composition used in the tests. Please add a sand column (Sand [%]) in table 3.
(R.145-155) 4. Discussion
Comment.
The discussion indicates the general nature of the research results and the need to increase the amount of research in order to identify binding relationships. The results of elastic concretes tests performed by other authors have not been indicated.
It must be corrected.
Please compare your own research with those given in the literature.
(R.156-168) 5. Conclusions
Comment.
The conclusions are very general, they do not arise directly from research. The conclusions concern recommendations for further research. The authors point to the negligible analytical material and the need for more detailed research in terms of determining the optimal range of selection of the bentonite mixture composition.
It must be corrected.
Please indicate the most important conclusions of the analyzes carried out.
(R.169) References
It should be corrected.
Please indicate the thematic articles in which the triple diagram is used for similar geotechnical analyzes.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Dear Cristian-Ștefan Barbu,
your manuscript is original, the topic is very actual, interesting and well write, so I agree for the publication in this form
Best regards
Author Response
Thank you very much for your kind revision!
Round 2
Reviewer 1 Report
Water/Cement/Bentonite Ratio Selection Method for Artificial Groundwater Barriers Made of Cutoff Walls
ID: water-1526897
Reviewer's reply.
The Reviewer is still convinced of the value of the research carried out and the results obtained. Doubts arise from the presentation of the research results. The graph of the composition of the new mixture (W + (C + B) + S) is a straight line in a triangular diagram. The form of presenting the results proposed by the Authors of the article is difficult to verify. The Authors themselves did not indicate relevant publications.
New response 1. R. (79-88) Figure 3.
It is impossible to explain the use of a triangular diagram to analyze the four independent variables constituting the basic configuration of the mixture: water + cement + bentonite + sand (W + C + B + S). The structure of the SAMPLE mix set presented in Figure 3 does not explain its real structure, which is a spatial set. The corner points of the R4 system represent 100% of the variable share, so for the surface axes of the diagram (WCB; WCS; WBS; CBP) the structure of the mixture is a set of points in space, while in Figure 3 it is a set on the plane (WCB) transformed on the surface axis (BCS) about the edge (BS) and the edge (CS). In the opinion of the Reviewer, the new Figure 3 does not bring the expected effect and should be removed.
New response 2. R. (79-88) Figure 3.
Please define the DOMINATED criteria and ranges. Does that indicate the percentage. For Water, Cement and Bentonite there are different percentage ranges (See table 3).
New response 3. Figure 10, 11, 12.
The Viscosity / Permeability / Variation figures presented are obtained from the research carried out. Each of them depends on the mixture composition (WCBS) (Mix Design). The designer of the composition of the mixture expects to indicate the optimal ratio of ingredients. Therefore, the analyzes should show the influence of this composition on the characteristics of the mixture. Variables (Viscosity, Permeability, Variation) are in a function relationship with (Water, Cement, Bentonite, Sand) or with parameters; W / C (Water / Cement), C / B (Water / Bentonite), Density). Figures 10, 11, 12 do not refer to the independent variables (Water, Cement, Bentonite, Sand, Density, Mix Design). In the opinion of the reviewer, figures 10, 11 and 12 should be removed. The reviewer points out again the need to supplement the article with the results showing graphical and functional dependencies of the type: (Viscosity, Permeability, Variation) = F (W / C, C / B, Density, Mix Design).
Author Response
Please see the attachment. Thank you for your review!
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
Reviewer's reply.
New02 response 1.
Thank you very much to the Authors for reminding the issues of spatial geometry. The purpose of the review, however, is to develop an article that would bring new elements to the development of the field of science. The article should be of a practical nature, so that its results could be used by engineers - mix designers (WCBS). The Reviewer had previously indicated the need to supplement the literature of the article. The presented literature only confirms the Reviewer's concerns about the lack of practical use of the triple nomogram for the analysis of the four-component mixture (WCBS). For this reason, the Reviewer indicated the need to develop functional dependencies, which the Authors did not do. The Reviewer classifies the article as a methodological one concerning the presentation of research results. Please answer the question: which values are to be used by the designer from the point cloud presented in the drawings? The value of the new v3 version of the article is the determination of the range of the recommended mixture composition in Figure 15.
New02 response 2.
The indicated full colors: blue, red and yellow are the corner points of the color legend in Figure 9. The area of domination is a color palette composed of a mixture of these colors. The domination area is the surface. In Figure 9, there are no visible boundaries between the dominance of individual components in the mixture. These limits influence the indications of the recommended mixing ratio. The range of the recommended mixture composition is shown in Figure 15. The recommended range excludes mixtures with the dominance of Bentonite (B) but also Water (W). Figure 9 shows the domination areas of: Water (W), Cement (C), and Bentonite (B). Please note that lines (139-141) indicate the workability ranges of the mixture, and table 3 shows the criteria for segregating aggregates. In Figure 9, please complete the color for the point (W65, C28, B7).
New02 response 3. Figures 10, 11, 12, 13, 14
Please mark the points that fall within the zone of the recommended mixture composition with one color, for example with a color such as the area of the recommended mixture composition in Figure 15.
New02 response 4. Tekst_v3. Lines (232-233). Figure 15.
Please compare the percentage ranges of the tested mixture components in Figures 2, 5, 6, 8 and Figure 15. In Figure 15, the results should be limited to the test range: Water (55-75), Cement (25-40), Bentonite (7-25). It is not possible to indicate a preferred mixture outside the limits of the tested composition.
Author Response
Please see the attachment. Thank you for your review!
Author Response File: Author Response.pdf
