Intumescent Coatings for Fire Resistance of Steel Structures: Current Approaches for Qualification and Design

Round 1

Reviewer 1 Report

This article summarizes diverse criteria of certification and assessment of intumescent coatings for designing the fire resistance of steel structures in national and European procedures.

What are the differences between the approaches for selecting Intumescent coatings in European and Asian countries?

The authors are suggested to review these articles in the introduction section: Doi: 10.3390/coatings12010072. Doi: 10.3390/act11020028 Doi: 10.3390/buildings11030082

What conditions and facilities are needed to perform experimental tests?

 

Author Response

Question: What are the differences between the approaches for selecting Intumescent coatings in European and Asian countries?

Response:Thanks to this Reviewer for her/his observation. Actually, our work focused on the analysis of the approaches for selecting and approving intumescent coatings specifically in Italy, within the European context. For this reason, the work is not mentioning the approaches used in the Asian countries. Nevertheless, thanks for this comment, we enhanced our research, discovering that the use of intumescent coatings in the Australasian region is significantly increasing in recent years [1] as alternative building code fire compliance in structural steel solutions. According to [2], the use of intumescent coatings in the Asia Pacific region is typically based on the application of the following standards:

-              BS476 Parts 20-22

-              EN 13381-8

-              ASTM E- 119/UL 263/NFPA 251

-              GB 14907 (Chinese fire test standard)

-              GOST (Russia and CIS region).

Although, the Eurocodes are globally recognized as the most advanced set of codes and various countries in the region, including India, are promoting their use [2].

In conclusion, we believe that there aren’t significant differences among the approaches for selecting Intumescent coatings in European and several Asian countries. This specific interesting comparison would require a detailed study that is out of the scope of this paper. Thanks again to the Reviewer for the suggestion of this future development.

[1]          A. Jowsey (2017). Using intumescent coatings to achieve building code compliance on steel structures, SESOC Journal 30(2):79-84

[2]          S. Nair, A. Jowsey (2013). Intumescent coatings: key considerations for specifiers, Asia Pacific Fire Magazine 47

 

Question:The authors are suggested to review these articles in the introduction section: Doi: 10.3390/coatings12010072. Doi: 10.3390/act11020028 Doi: 10.3390/buildings11030082

Response: Thanks for your suggestions; however the authors do not find these papers very pertinent to the topic covered by the paper, but in the future the suggested papers will certainly be considered as references. However, the bibliography was extended adding the following papers:

1. Beh J.H., Yew M.C., Saw L.H., Ming Kun Yew M. K., (2020) Fire Resistance and Mechanical Properties of Intumescent Coating Using Novel BioAsh for Steel. Coatings 2020, 10(11), 1117; https://doi.org/10.3390/coatings10111117
2. de Silva D., Bilotta A., Nigro E. (2017). Effect of the thermal input on the behavior of intumescent coatings. Applications of Fire Engineering - Proceedings of the International Conference of Applications of Structural Fire Engineering, ASFE 2017 Pages 325 - 334 International Conference of Applications of Structural Fire Engineering.
3. Kang S., Kwon M., Choi J.Y., Choi S. (2019). Thermal Boundaries in Cone Calorimetry Testing. Coatings 2019, 9(10), 629; https://doi.org/10.3390/coatings9100629

Question:What conditions and facilities are needed to perform experimental tests?

Response: The fire behaviour of IC mainly depends on dry film thickness (DFT), adhesion during normal and fire situation and swelling reaction in fire situation. Therefore, in order to have a full characterization of these protections several tests have to be performed before and after its application. In particular:

• the fire behaviour is characterised and tested with a standard furnace, as described in paragraph 3.1. In order to clarify this aspect, the following sentence was added at page 5 lines 184-186: “The standard furnace is generally 4 m long and 3 m wide, equipped with several burners, controlled by programmable logic controller to simulate different fire curves.”
• the thickness and adhesion tests can be performed with different facilities, as described in paragraph 4.3.

Reviewer 2 Report

The submitted work provides an overview of the certifications and design of systems in which intumescent coatings are employed for improving fire resistance of steel structures. It is an interesting and well-written work. Although this work seems to be more an interesting technical report with low scientific significance (no new results are provided), its publication is expected to gain great readers’ attention. In this context, considering this work as a review paper, I am positive for its publication.

Author Response

Thanks a lot  to the reviewer for him/her positive feedback.

Reviewer 3 Report

The paper do not reveal  scientific character. It was intended as the guidance concerning certification procedures of the IC anti-fire multi- layer coatings on the steel structures required in Italy, in relation to the EU normatives and regulations. The required tests and procedures are presented in a very general way, as the subject is quite complicated. The paper is written very well and supplies scientists with the informations concerning a complicated industrial and low requirements for the use of the defined products from the fire-protected steels in practice, commonly not well known for them. The  decision must be taken by the Editor,  the paper may be accepted in the present form or redirected to the more industrial magazines.

Author Response

Thanks a lot  to the reviewer for him/her feedback.

Reviewer 4 Report

The manuscript provides a comprehensive overview, based on different standards and European norms, regarding the certification, design and control of fire protection for steel structures, to extend their fire resistance. The suggested technical solution addressed in the current study is the use of intumescent coatings. The topic is interesting and has a real importance in industry, however, the subject was already approached in literature. The manuscript is consistent, organised and well written, though there are a few issues that need to be addressed towards the improvement of this work before publication.

Some observations are summarised below:

• The authors should carefully proof-read spell check to eliminate grammatical and spelling errors: line 101: top coat have, …and to promote, line 193: have to be used, line 426: . Conclusions
• Line 173: It is not clear what Am/V (A – surface, V – Volume?)
• More references are encouraged to be consulted.

Author Response

Thanks to this Reviewer for her/his observations. The paper was read carefully, also implementing the spelling errors observed by the reviewer. The bibliography was extended, as suggested. Please consider the attached new version of the paper.

Round 2

Reviewer 1 Report

Please illustrate the contribution and novelty of your research clearly. The literature review is not sufficient. The introduction section is very briefly organized. I recommend expanding the introduction section by considering the mentioned references. Also, please explain the limitation and assumptions in the manuscript.

Author Response

Thanks again to the reviewer for his/her suggestions; all the changes has been implemented, with a significant improvement of the work. Please consider the following reply.

The use of structural products or materials requires the certification of their main essential characteristics. The procedure to achieve this goal is not always known, particularly in the case of new or innovative products, and sometimes even not very clear due to the existence of several standards. In this context, the proposed paper is intended to be a technical review suppling scientists with an overview of required tests and procedures to assess and certify IC systems for steel fire-protection in Italy, in relation to the EU normatives and regulations.

Thanks to the Reviewer’s comment, the contribution of this paper has been now emphasized in the Introduction and the following text is added at page 3 lines 102-106: “Indeed, the complicated industrial and low requirements for the use of these products for the fire-protected steels in practice is commonly not well known. Thus, the work is intended as a guidance concerning certification procedures required in Italy, in relation to the EU normatives and regulations. A general outlook of the required tests and procedures is presented.”

Furthermore, the authors included in the paper all the references suggested by the reviewer; please consider the new version of the attached paper.

 

 

Author Response File: Author Response.pdf