Influence of the Geosynthetic Type and Compaction Conditions on the Pullout Behaviour of Geosynthetics Embedded in Recycled Construction and Demolition Materials
Round 1
Reviewer 1 Report
The manuscript with the title “Influence of the Geosynthetic Type and Compaction Conditions on the Pull-out Behaviour of Geosynthetics Embedded in Recycled Construction and Demolition Materials” investigated pull out experiments using two types of geotextile (GGR) and geogrid (GCR) with the different conditions of recycled construction and demolition (C&D) material in view of compaction and moisture content. The main value of the study is using recycled materials which would lead researchers and readers to understand Geosynthetics reinforced C&D waste behaviour; however, some specifications might require more discussions and considerations. The points are stated as below:
- Abstract: The results need to be quantitatively mentioned to present the acquired results clearly.
- The introduction can be enhanced using more recently published papers in the context, as no 2021 paper is covered in the manuscript.
- L 210 to L 212: The authors discussed the shear strength parameters of the used recycled materials; however, the nature of C&D materials and involved uncertainties due to the aggregate breakage was not considered. Thus, authors must justify this issue. Moreover, adding the repeated tests’ statistical properties is suggested to clarify how much the result may deviate from the reported values.
- L 242 to L 246: In the “…it should be remembered that the pull-out resistance of the geogrids results from the skin friction along with the reinforcement and the passive thrust on the transversal members of the geogrid…” sentence, the effect of different mechanical characteristics of the GGR and GCR is missed. Secant stiffness of GGR is nearly three times larger than that of GCR, which would directly affect the pull-out results. It is required that authors discuss this difference in their results to reflect this difference.
- L 492 to L 493: This sentence needs to be rewritten more specifically and mentions the exact effect of moisture content parallel to the pull-out capacity effect.
- The conclusion section is very general, and there are no quantitative briefing results.
- Some environmental aspects such as “… alternative to the natural resources…” are mentioned in the manuscript. It should be noted that environmentally friendly materials must also obey the ground and water pollution regulations. Thus, the authors are encouraged to add appropriate regulations and address the required procedures for choosing C&D materials.
Author Response
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Author Response.pdf
Reviewer 2 Report
- The article presents essential contributions to the use of geosynthetics embedded in recycled construction and demolition materials to application in the construction of reinforced embankments.
- Experimental investigation is robust with 60 pullout tests.
- Did the vertical confining pressure for 10, 25, and 50 kPa consider the structural fill above the geosynthetic used? What is the value of the structural fill above the geosynthetic? (Figure 5a).
- In Tables 8 and 9, I recommend putting a column with the value of the shear strength of the backfill material.
Author Response
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Reviewer 3 Report
- The title is too long: Maybe revised to a shorten one
- Abstract: Line 20: Meaning of the line is not clear" Test results have pointed out that pullout resistance of the geogrid
is higher than that of the geotextile and is achieved at lower displacements." - Line 22: "conversely the pullout capacity of the geotextile increased." kindly clarify the meaning of it?
- Line 24: " effect of the degree of compaction on the geogrid pullout resistance was inconclusive" how do authors can claim this?
with the compaction of soil: geogrid pullout resistance will increase. - Line 66-83: could be sum up in a table for better clarity to its readers
- Line 160: "80% or 90% of the maximum dry density (MDD)." why did the authors select 80-90% MDD when the recommended range for the field compaction is min 95% of MDD? Refer Book by Jie Han: Ground Improvement Using Geosynthetics
- For the completeness of the literature review and applications of the C&D waste materials should be added in the intro, so that the readers can be influenced to work research in this area. I could see a similar work here
https://0-doi-org.brum.beds.ac.uk/10.1007/978-981-16-1993-9_21 - Fig 7(a): why there is so much variation difference in sample 1 and sample 3 observations? authors must mention the probable reason behind it.
- At a level of 100 mm displacement, the difference in pullout force is very large: nearly 20 KN? explain it.
- Line 338-340: Can authors justify the claims made by them "While in the geogrid, due to its large apertures (Figure 3a), the pullout behaviour will be more influenced by the shear strength
of the backfill material, the hydraulic properties of the geotextile, particularly its water absorption capacity, will influence its pullout performance." - The authors must explain, how did they prepare the uniform sand bed with MDD 80/90%. Preparation of the sand bed at uniform density is crucial to simulate the field condition as well as get the repeatability in the findings from the experimental program. As a reviewer, I am interested to see the authors' replies.
- Did the authors perform shear strength characterization of the C& D material? If yes, add complete information to the manuscript.
- Also mention, what are the strength parameters with a mention of the level of the confining pressure.
- In Tables 8 and 9, how did the authors calculated fb values? explain in detail, which two values were taken to get the ratio?
- It will be better to add them in the appendix also for the better clarity of its readers.
- Out of a total 44 number of references, 10 self-citations must be avoided. Keep it low.
- Authors are advised to add some photographs of the test apparatus/ experimental setup.
Author Response
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Reviewer 4 Report
The paper experimentally investigates the pullout behaviour of geosynthetics embedded in recycled construction and demolition materials, considering different compaction conditions, geosynthetic types and moisture content. Despite the fact that the authors might put efforts to perform the model tests, the approach and findings are incremental in nature and make a limited advance in the academic field or practical applications. The study is primarily confirming and strengthening existing knowledge and understanding. Moreover, the authors seem to fail to suitably provide a proper justification and a detailed comparison with previous works along a similar line of research.
Comments for author File: Comments.pdf
Author Response
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Round 2
Reviewer 4 Report
No additional comment.
