Comparison between the Effects of Normal Rain and Acid Rain on Calcareous Stones under Laboratory Simulation

Round 1

Reviewer 1 Report

General comments

 

Authors proposed a comparison between the effects of normal rain and acid rain on calcareous stones by a rain fall simulation in the laboratory. The article is generally interesting, and contents are overall well organized. However, the work needs to be improved according to the specific suggestions given to the authors, especially the thermal (frost) effect.

English needs just a few controls of spelling but overall is quite good.

 

 

Specific comments:

 

 

Title

 

Instead of “Comparison Between the Effects of Normal Rain and Acid Rain on Calcareous Stones”, I suggest writing “Comparison Between the Effects of Normal Rain and Acid Rain and thermal ageing on Calcareous Stones under laboratory simulation”

 

Abstract

 

The abstract is generally well written. However, conclusions need to be improved with a resume of results achieved.

 

 

Introduction

 

Introduction is weak and the effects of harsh temperature, rain acidity and climate change together with the benefits in using digital reconstructions should be enhanced.

 

Lines 35 – 37. Please explain better the effects of climate change in the indoor environment.

 

Lines 39 - 44: please clarify which are some of the “scientific solutions” needed to solve that threat. Bibliography is missing.

 

Line 47: change “atmospheric water” with “water molecules”.

 

Lines 47 – 48: pH of rainwater in equilibrium with the CO₂ present in an unpolluted atmosphere with low total dissolved solids is ~5.6, so basically is a slight acidic water. You must deepen that and can cite these references:

http://www.lneg.pt/iedt/unidades/16/paginas/26/30/185

https://doi.org/10.1016/j.jobe.2022.104495

DOI 10.1007/s11270-008-9774-0

https://www.science.org/doi/10.1126/science.184.4142.1176

 

 

Methods

 

Lines 72-73-74: how many TAP in 20 years? Please specify

 

Authors must improve the bibliography referring to other studies where simulation of acid rain was executed. Here some examples:

https://doi.org/10.1016/j.jobe.2022.104495

https://link.springer.com/article/10.1007/s12665-018-7467-6

https://biblio.ugent.be/publication/8056238

In the latter, 3D scanning was conducted.

 

Cut and paste lines from 56 to 65 to materials paragraph

 

 

 

Materials and methods

 

Cut and paste lines from 56 to 65 in this paragraph. 

Here, a more accurate description of mineralogical, petrographic, superficial texture and density/porosity of the samples is fundamental to correlate the decay of the stone to the damage observed in results section (i.e., interpretation from lines 213 to 216 need to be strengthen).

 

Fig.3: please specify the meaning of N, 2GO, 3GO and ac in the caption.

 

 

 

Results

 

Line 121: change cover with “hydrophobic coating”

 

How do authors distinguish the effect of acid rain from the effect of freeze-thaw cycles? The effect of thermal changes must be deal with.

 

Authors should explain better the relation between loss or gain of materials and presence or absence of hydrophobic treatments

 

 

Conclusions

 

Please avoid conclusions that are too general. Describe this section considering that you should focus on the findings of the methodology and the results obtained. Furthermore, highlight the outcomes for the scientific community and the implication for the long-term assessment of stone weathering due to climate change (and thermal ageing, mostly frost damage).

Author Response

Thank you very much, because after your comments the paper has won in quality.

Author Response File: Author Response.docx

Reviewer 2 Report

I write some suggestions:

1) The graphene oxide is mentioned just in the 5.Conclusions, while before it is just defined as "protective cover", I would reccommend to introduce and describe this material before;

2) in the section 2. Materials and Methods, lines 70-80, it would be necessary to clealry define the rain  with parameters like: intermittent or continuous rain, intensity (es. mm/5 minutes), total amount of rain in what time (mm/hours) (after 1 hour, yearly intercepted rain in the city of Leon how many mm?); then there is a simultaion of 20 hours, but it is not explained the rain scheduled timing. It is important in order to contextualize the condition and the limits (if any) of the simulation;

3) another useful specification is the description of the rain simulator;

4) the 4.Discussion may add some little suggestion regarding how to interpretate the data like the difference from simulation and reality, just from the technical point of view (rain concentrate in a little period vs normal rain; new cube samples vs statues... just as examples)

5) I think that the conclusions should be wider and more specific starting from this research: eg how to continue the research (what it is missed linking the results to real conditions), possibilities and limits of the application of this material at a real scale on monuments; the quote of carbon footprint line 254 is not clear.

Author Response

Thank you very much for your effort and for explaining your comments.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Dear authors,

thank you for the point to point clarifications that allowed you to improve the quality of your manuscript.

You must just to correct a sentence in line 113 of the proof: "It presents sparitic limestone filling in fissures and cavities". Change with "It is characterized by the presence of spastic cement filling in fissures and cavities".

Sparitic limestone doesn't exist. Sparite is a cement resulting from the precipitation of carbonate-rich solutions that circulate through pores, capillaries, fractures and other discontinuities of the rock.

 

That's all

Good luck!

 

Author Response

Thank you very much for your change in the sentence. It has been changed as you suggested to "It is characterized by the presence of spastic cement filling in fissures and cavities".

And thank you also for explaining us the reasons to do that, we have learnt it for the future. 

All the best!

María

Author Response File: Author Response.docx