Design and Characteristics of a Hybrid Wood-Soil System Made from Casuarina glauca Wood

Round 1

Reviewer 1 Report

The Manuscript entitled "Design and Characteristics of a Hybrid Wood-Soil System made from Casuarina Glauca Wood", presents very interesting topic. The authors present the unique approach to solving a problem in structural designing of the one floor classroom. 

They presented the motivation of the study which is reasonable and proved the need of conducted research. However beside the strong introduction the Manuscript benefits from the revision. The two major issues are:

- there is lack of numerical analyses which may evaluate if the model and values of the destruction forces are reasonable during the tests and if the work itself is correctly designed. Maybe some smaller issues in the design might be beneficial in terms of usage of the material. 

- another major issue are the conclusions which are lacking with the contribution into the body of knowledge. They just refer to the study instead of to the scientific field. Therefore there is a need to present where else such structures might have been build. In what cases (forces and conditions)

Moreover the Manuscript would benefit from revising smaller issues such as:

- The presenting of the whole scheme of the building would present more clarity to the work. One wall is not enough,

- some typo mistakes which leads to the error with "Error! Reference source not found." (e.g. line 156) 

- figure 6 must be revise.

Overall merit of the Manuscript is very positive however the Manuscript benefits from the revision. 

 

Author Response

Reviewer comment:

"The Manuscript entitled "Design and Characteristics of a Hybrid Wood-Soil System made from Casuarina Glauca Wood", presents very interesting topic. The authors present the unique approach to solving a problem in structural designing of the one floor classroom." 

Authors response:

The authors thank the reviewer for the comment. 

Reviewer comment:

"They presented the motivation of the study which is reasonable and proved the need of conducted research. However beside the strong introduction the Manuscript benefits from the revision. The two major issues are:

- there is lack of numerical analyses which may evaluate if the model and values of the destruction forces are reasonable during the tests and if the work itself is correctly designed. Maybe some smaller issues in the design might be beneficial in terms of usage of the material. 

- another major issue are the conclusions which are lacking with the contribution into the body of knowledge. They just refer to the study instead of to the scientific field. Therefore there is a need to present where else such structures might have been build. In what cases (forces and conditions)"

Authors response:

The authors thank the reviewer for the comment. The revised manuscript has been adjusted as follows:

• The comparison between the results of the testing and the design criteria was added in sections 3.1.1 and 3.1.2 in order to judge the structural capacity of the structure according to the Egyptian loading code specified loads.
• The comparison between the results of the testing and the design criteria was added in sections 3.1.1 and 3.1.2 in order to judge the structural performance of the structure according to the Canadian code serviceability criteria.
• Figure 14 was added to further explain the differences in numbers and compare them to the design wind load, further explanation of this comparison is shown at the end of section 3.1.2.
• More general points of conclusion have been added to the conclusions section in the revised manuscript.

Reviewer comment:

"The presenting of the whole scheme of the building would present more clarity to the work. One wall is not enough"

Authors response:

The authors thank the reviewer for the comment. The loading was carried per side in the transverse and the longitudinal directions and the data were measured from the two opposite walls per direction as shown in figure 2 and figure 3. The measured data from each two opposite walls were recorded and plotted on the load-deflection curves shown in figures 4, 7 and 12. So the performance of the whole scheme of the building was assessed in the horizontal plane in two directions for two opposite sides per direction.

Reviewer comment:

"some typo mistakes which leads to the error with "Error! Reference source not found." (e.g. line 156)"

Authors response:

The authors thank the reviewer for the comment. There was an issue in the figure caption numbering that caused this error, the authors checked and corrected this situation and double checked that this error doesn't exist in the word document version attached.

Reviewer comment:

"figure 6 must be revise."

Authors response:

The authors thank the reviewer for the comment, the figure contrast has been changed and the figure size have been increased to make it clearer.

Reviewer 2 Report

The paper entitled "Design and Characteristics of a Hybrid Wood-Soil System made from Casuarina Glauca Wood" complies with the requirements for publication. There are some aspects that need to be corrected/completed, as follows:

- the name of the NGO can be interpreted as indirect advertising and its removal is recommended;

- bibliographical references are missing from the text (lines 156, 162, 171, 177, 233, 236, 291, etc.);

- the English style and language must be revised (eg: line 193 "is assumed to emit were" or line 214 "is to be constructed" and others);

- the evaluation of carbon emissions is established with a methodology different from the established one using an LCA-type analysis - a brief presentation of the evaluation method from the source from where the authors took the values is necessary;

- the authors are recommended to present the comparative, tabular and graphical presentation of the differences obtained when testing horizontal actions for the two models tested;

- also, if no reference is made to the values obtained from the structural calculation, the authors are recommended to analyze whether the presence of the paragraph from lines 133-142 is necessary.

The conclusions must be reformulated - it is necessary to substantiate them based on the results obtained.

Author Response

Response to reviewer 2

Reviewer comment:

"the name of the NGO can be interpreted as indirect advertising and its removal is recommended" 

Authors response:

The authors thank the reviewer for the comment. The name of the NGO has been removed in the adjusted version of the manuscript.

Reviewer comment:

“bibliographical references are missing from the text (lines 156, 162, 171, 177, 233, 236, 291, etc.)”

Authors response:

The authors thank the reviewer for the comment. Actually, there were no citations within these lines as the source of all of the information in these lines are in-house however may be the reviewer meant the errors in cross-referencing to the figure captions that existed at these lines. There was an issue in the figure caption numbering that caused this error, the authors checked and corrected this situation and double checked that this error doesn't exist in the word document version attached.

Reviewer comment:

 “the English style and language must be revised (eg: line 193 "is assumed to emit were" or line 214 "is to be constructed" and others);”

Authors response:

The authors thank the reviewer for the comment. The mentioned mistakes have been corrected in the adjusted manuscript and it was proof-read and the language was enhanced.

Reviewer comment:

“the evaluation of carbon emissions is established with a methodology different from the established one using an LCA-type analysis - a brief presentation of the evaluation method from the source from where the authors took the values is necessary”

Authors response:

The authors thank the reviewer for the comment. The reference from which the carbon emissions per unit weight and the carbon emissions per unit volume have been acquired has reached these figures based on a life cycle analyses for several constructed buildings so these figures already include such effect into account. Further clarification has been added in section 2.3

Reviewer comment:

“ the authors are recommended to present the comparative, tabular and graphical presentation of the differences obtained when testing horizontal actions for the two models tested”

Authors response:

The authors thank the reviewer for the comment. The revised manuscript has been adjusted by adding a graph numbered as Figure 14 to further explain the differences in numbers and compare them to the design wind load, further explanation of this comparison is shown at the end of section 3.1.2.

Reviewer comment:

“also, if no reference is made to the values obtained from the structural calculation, the authors are recommended to analyze whether the presence of the paragraph from lines 133-142 is necessary.”

Authors response:

The authors thank the reviewer for the comment. The revised manuscript has been adjusted as follows:

• The comparison between the results of the testing and the design criteria was added in sections 3.1.1 and 3.1.2 in order to judge the structural capacity of the structure according to the Egyptian loading code specified loads.
• The comparison between the results of the testing and the design criteria was added in sections 3.1.1 and 3.1.2 in order to judge the structural performance of the structure according to the Canadian code serviceability criteria.

Reviewer comment:

“The conclusions must be reformulated - it is necessary to substantiate them based on the results obtained.”

Authors response:

The authors thank the reviewer for the comment. The revised manuscript has been adjusted to include more points within the conclusions.

Reviewer 3 Report

It is an interesting article but it should be improved. It seems that it was written in a hurry. There are confusing passages and many phrases are repeated.

It can be published after corrections and additions are made according to the recommendations in the Report.

Please, check also the correctness of the sentences written in English.

Comments for author File: Comments.pdf

Author Response

Reviewer comment:

"ABSTRACT

Lines 15, 16, 17: Replace timber with: wood

Line 15: Replace modernity with: global warming

Line 21: Delete “The structure was analyzed and designed structurally”

Line 22: Replace „perpendicular horizontal directions” with ... two horizontal planes: lateral and transverse

Line 23: Mention which are the point of weakness obtained after testing

Line 24: Add that adjust model included X-braces (to underline the differences between models)

Line 24: „have sufficient strength” - compared with something!- or within limits mentioned in construction guide or standard, or rules etc.

Keywords: Please, add: structural testing " 

Authors response:

The authors thank the reviewer for the comments. All the reviewer’s recommendations have been implemented in the revised manuscript.

Reviewer comment:

"1. INTRODUCTION

Line 49: Try to replace “On the other hand..” with other words, because it is repeated many times in the introduction

Lines 50-52: “One of the reasons for this increase in the costs of housing is the increasing costs of construction materials”. This phrase should be deleted (It is repeated!)

And the following phrase .....”Hence, ...................................of low-cost raw materials such as waste materials” – should be moved after line 60........ so that the text to have continuity and to be more clear.

Line 60- Please, add also: .. beside waste, underutilized local wood species could be o source of material for constructions

Line 66: How much is the moisture content?

Line 86 – Delete: however, and Page 2 of 3

 

Lines 89-97- Please, check the correctness of the terms used - It is repeated the term structurally many times in the same phrase,… than, …. was calculated... to calculate... etc. Also, counterpart to be replaced by concrete reference material, (or control system, or control structure). " 

Authors response:

The authors thank the reviewer for the comments. All the reviewer’s recommendations have been implemented in the revised manuscript.

Reviewer comment:

" It is important to add here a table with some characteristics of the wood raw material used (Casuarina Glauca): density, moisture content, MOR, MOE or others which are important for constructions.- Move them from the lines 127-130." 

Authors response:

The authors thank the reviewer for the comments. The required table have been added in the revised manuscript and the text has been adjusted accordingly.

Reviewer comment:

" Line 104: What means non-accessible roof? " 

Authors response:

The authors thank the reviewer for the comments. The definition of a non-accessible roof has been added.

Reviewer comment:

" Line 107- the dimension in figure are in m?!

It is necessary to present other figures to show all the elements of the structure and the distance between them (for the first model and also the adjusted model). How tall is the structure? " 

Authors response:

The authors thank the reviewer for the comments. The caption in the figure has been corrected to be m instead of cm. The height of the tested structure is shown in figure 3. The dimensions didn’t change from one model to the other as the connections and the bracing shape are the only items that changed as explained in the manuscript. Unfortunately the size limit of the manuscript doesn’t enable the authors to add a figure for each element however the authors added figures for the changes in connections and bracing from the original model to the adjusted version.

Reviewer comment:

" Line 110: Which are the wooden members? Add also the dimensions of all wooden elements of the structure and the type and dimension of the connections used for both structures (first model and adjusted model). In a table should be better. " 

Authors response:

The authors thank the reviewer for the comments. All structural members are wooden as explained within the manuscript. The dimensions of the wooden elements in the full-scale designed structure are added in line 140 of the adjusted manuscript in lieu of the reviewer’s comment. The dimensions of the connections are shown in Table 2 and further discussed in the text between lines 335 and 345 while their shapes are shown in figures 10 and 11.

 Reviewer comment:

" Line 111: Please check the correctness of the sentence (… infill for insulation and isolation purposes) " 

Authors response:

The authors thank the reviewer for the comments. The sentence has been adjusted in the adjusted manuscript in lieu of the reviewer’s comment.

Reviewer comment:

" Lines 130-133: Based on which rules or standard did you established this strength limit? " 

Authors response:

The authors thank the reviewer for the comments. The concrete compressive strength of 30 MPa and the steel yield strength of 360 MPa are based on the most commonly available materials and most common grade of materials in Egypt as explained in the adjusted version of the manuscript.

Reviewer comment:

" Line 155 – It is better: A scale factor of 1:3 " 

Authors response:

The authors thank the reviewer for the comments. The sentence has been adjusted in the adjusted manuscript in lieu of the reviewer’s comment.

Reviewer comment:

“Lines 156, 162, 171, 177, 233, 236, 249, 291: - Reference??”

Authors response:

The authors thank the reviewer for the comment. Actually, there were no citations within these lines as the source of all of the information in these lines are in-house however may be the reviewer meant the errors in cross-referencing to the figure captions that existed at these lines. There was an issue in the figure caption numbering that caused this error, the authors checked and corrected this situation and double checked that this error doesn't exist in the word document version attached.

Reviewer comment:

“Lines 193-194- Idem lines 206- 210 -Please reformulate the sentence and pay attention to the meaning of the numbers. What does this figure represent? „0.35 kg of CO2/kg of timber”!?

- It should be mentioned that it is about CO2 emissions throughout the full life cycle including production, transport, building, application, demolition and removal.

-A wooden house frame as construction absorbs 9.5 tones of CO2 from the atmosphere.

-As material, wood, has absorbed a net 1.7 tones of CO2 from the atmosphere compared to concrete which released 159 kilos of CO2 into the atmosphere.”

Authors response:

The authors thank the reviewer for the comment. The reference from which the carbon emissions per unit weight and the carbon emissions per unit volume have been acquired has reached the figures mentioned in the manuscript based on a life cycle analyses for several constructed buildings so these figures already include life cycle effects into account. Further clarification has been added in section 2.3. However it is worth to note that several studies exist with several reported figures for carbon emissions so the authors had to stick to one source of information in order to fairly compare an HWS system to an RC system based on information from the same source in order for the data to be comparable.

Reviewer comment:

“Lines 344- 354- Should be deleted. It is repeated what was said in the lines 191-200.

Please, reformulate the results obtained.”

Authors response:

The authors thank the reviewer for the comments. This part has been adjusted in the adjusted manuscript in lieu of the reviewer’s comment to reduce repetitiveness in the text.

Reviewer comment:

“Lines 357-362. Should be deleted. It is repeated what was said in the lines 207-212.

Please, reformulate the results obtained.”

Authors response:

The authors thank the reviewer for the comments. However, the authors couldn’t find any repetition when comparing the mentioned lines to lines 207-212.

Reviewer comment:

“Line 374: table 3: the connectors are not included in the total costs?”

Authors response:

The authors thank the reviewer for the comments. The cost of the HWS includes the additional costs of the added steel connectors within the cost of the skeleton together with the costs of the wooden members. This issue has been clarified in the adjusted version of the manuscript.

Reviewer comment:

“Lines 376- 380- Please, reformulate to specify more clearly the differences in failure in the lateral versus the transverse testing.”

Authors response:

The authors thank the reviewer for the comments. Additional explanation for this part has been added between lines 430 and 438 in lieu of the reviewer’s comment.

Reviewer comment:

“Lines 379-381: It should be reformulated like this for example: Similar behavior was obtained by (11) and (13) for their structures made of Glauca wood trusses but having different design and dimensions”

Authors response:

The authors thank the reviewer for the comments. The sentence was reformulated in lieu of the reviewer’s comment.

Reviewer comment:

“Line 384: These results fall within the limits mentioned in the standards or rules in the wooden construction?

In the discussion part should be mentioned the maximum deflection recorded (if possible), if there are cracks and other aspects observed.

What quantities of wood material were used in the 2 types of structures made and how they influenced the costs?”

Authors response:

The authors thank the reviewer for the comments. The comparison of the deflections to the standards is mentioned in line 429 in lieu of the reviewer’s comment. The amount of wood used has been mentioned in line 393 in lieu of the reviewer’s comment. Further explanation of its effect on costs is added in lines 442-444 in lieu of the reviewer’s comment.

Reviewer comment:

"5. CONCLUSIONS

Should be added that Casuarina Glauca wood proved that it is a good material for simple constructions in a hybrid wood-soil system.

Line 396: ...” high capacity” based on which rules or construction guide?

Lines 398- 399: Replace counterpart by reference structure or control structure/system as is defined in the Method chapter " 

Authors response:

The authors thank the reviewer for the comments. All the reviewer’s recommendations have been implemented in the revised manuscript.

Reviewer 4 Report

The article should be scanned to write properly the wood species name in proper scientific convention. It should be Casuarina glauca. The G in glauca should be in lower case. 

The referencing to tables in figures in the text got affected by the editing software of the authors lost track of many of the table and figure linkages. Please review the whole text to recover the proper linkages and then review the numbering so that the table and figure numbers appear correctly, not the case in the attached manuscript as you can see. 

In the results section, some methods are repeated or explained. All methods should be detailed in the methods section and not be repeated in the results section. 

The most import correction that needs to be made is the following. In the evaluation of the HWS, no data is provided about the steel connectors, plates, nails and screws, neither about their or CO2 emissions. In such constructions, especially with the revised designs, these will not be negligible. This will affect the discussion and conclusions. The current conclusions are overly positive and optimistic. Once the steel connectors will have been taken into account, the difference between the wood based and cement based systems will be much small. This complement needs to be brought, there is no escaping it. 

Also the suggestion about the alternative wood drying method is overly positive. This should be brought only as an idea for future evaluation, no conclusion should be brought at this stage about the cost or CO2 performance of quicklime drying. I for myself have no idea of its cost and CO2 performance. Conclusions about it should be left to future work. 

Comments for author File: Comments.pdf

Author Response

Response to reviewer 4

Reviewer comment:

" The article should be scanned to write properly the wood species name in proper scientific convention. It should be Casuarina glauca. The G in glauca should be in lower case." 

Authors response:

The authors thank the reviewer for the comments. The change been implemented in the revised manuscript in lieu of the reviewer’s comment.

Reviewer comment:

" The referencing to tables in figures in the text got affected by the editing software of the authors lost track of many of the table and figure linkages. Please review the whole text to recover the proper linkages and then review the numbering so that the table and figure numbers appear correctly, not the case in the attached manuscript as you can see. " 

Authors response:

The authors thank the reviewer for the comments. All figure and table captions and their cross-referencing has been changed and double-checked in the revised manuscript in lieu of the reviewer’s comment.

Reviewer comment:

" In the results section, some methods are repeated or explained. All methods should be detailed in the methods section and not be repeated in the results section." 

Authors response:

The authors thank the reviewer for the comments. The results section was adjusted to avoid repetitions in lieu of the reviewer’s comment.

Reviewer comment:

"The most import correction that needs to be made is the following. In the evaluation of the HWS, no data is provided about the steel connectors, plates, nails and screws, neither about their or CO2 emissions. In such constructions, especially with the revised designs, these will not be negligible. This will affect the discussion and conclusions. The current conclusions are overly positive and optimistic. Once the steel connectors will have been taken into account, the difference between the wood based and cement based systems will be much small. This complement needs to be brought, there is no escaping it." 

Authors response:

The authors thank the reviewer for the comments. The contribution of the steel connections to the carbon emissions have been included in the adjusted version of the manuscript in lieu of the reviewer’s comment as shown in sections 2.3 and 3.2.

Reviewer comment:

" Also the suggestion about the alternative wood drying method is overly positive. This should be brought only as an idea for future evaluation, no conclusion should be brought at this stage about the cost or CO2 performance of quicklime drying. I for myself have no idea of its cost and CO2 performance. Conclusions about it should be left to future work." 

Authors response:

The authors thank the reviewer for the comments. The wording of this part has been changed in lieu of the reviewer’s comment and recommendations have been added in section 5.

Round 2

Reviewer 1 Report

The only thing which should be now revised is the figure 10 and 11 with addition of some dimensions. 

After this minor review it can be published. 

Author Response

The authors thank the reviewer for the comment. Dimensions have been added to the two figures in lieu of the reviewer’s comments.