Investigation of Behavior of Masonry Walls Constructed with Autoclaved Aerated Concrete Blocks under Blast Loading

Round 1

Reviewer 1 Report

In this study, the authors have focused on an interesting topic to identify, investigate and analyze the behavior of masonry walls made of AAC lightweight concrete units under the effect of blast loading. The crack growth, displacements, stress distribution, and energy absorption of different models of this type of wall were investigated using FE modeling approach. 

The topic relevance and quality of the research make it worthy of publication, if the following comments are implemented:

1. What are the dynamic properties used for numerical simulation and analysis under high strain rate conditions?

2. The novelty of the work should be better highlighted in the Introduction section (the last paragraph).

3. Different parts of Figures 4, 8, and 12 are not clearly specified. The authors should integrate the names with figures, so the order and arrangement do not mess up.

4. In the Conclusions, "it can be stated that masonry walls made with AAC do not have a good explosion resistance and would need retrofitting". In my opinion, one or more retrofitting methods should be suggested.

5. There are several minor grammatical problems or inappropriate use of English in the context. I would recommend that you pass this paper to a native, or highly accomplished English speaker, to check over the revised version.

6. The authors presented results for several AAC walls under lateral blast loading considering different stiffnesses, stand-off distances and charge weights. Three different boundary conditions were initially mentioned (Figure 6), but it seems these were not included the developed models nor reported in Table 3. Please clarify this apparent inconsistency and give further explanations on the reason for selecting those boundary conditions.

7. It is not clear if any axial load (as gravitational or quasi-static load) was applied in the finite element model of the walls.

8. Further explanation and discussions of the results can be beneficial to improve the readability of the manuscript.

9. The following relevant references concerning the out-of-plane failure of masonry walls can be reviewed and cited in the revised version:

1-    doi: 10.1080/15583058.2012.665146

2-    doi: 10.3390/app10051576

3-    doi: 10.1142/S0219455419501372

4-    doi: 10.1016/j.engstruct.2021.113233

5-    doi: 10.1680/jencm.21.00010

6-    doi: 10.1016/j.engstruct.2011.02.012

Author Response

Please see the attachment.

Reviewer 2 Report

This study aims to investigate the behavior of masonry walls constructed with autoclaved aerated concrete blocks under blast loading. For this purpose, by performing experimental testing, material properties including compressive, tensile, and shear strength values were obtained which have been used in finite element (FE) models of AAC-based masonry walls in ABAQUS. Three different wall thicknesses (i.e. 15,20 and 25) and different blast scenarios were selected to perform numerical analysis. The results showed inappropriate behavior of AAC materials against explosion loads, especially in close in-range blast loadings. From the reviewer's point of view, the paper is well written and the subject could be well related to the theme of the journal. However, before publishing, the following suggestions and comments should be taken into consideration. It should be noted that some comments have been also left on the attached file that should be considered in addition to the following comments in the revised manuscript.

-         Autoclaved aerated concrete blocks are produced in different sizes and dimensions by factories. The authors need to explain why the dimensions of AAC blocks were 600×250 mm with thicknesses of 15, 20, and 25 cm (page 8, line 298).

-         The text is well written but there are several grammatical problems or inappropriate use of English in the context. I would recommend passing the revised paper to a native, or highly accomplished English speaker, to check over.

-         All the parameters in Eqs. 10 to 13 must be defined after the equation in the context (if they are not referred before) on page 7, lines 255-263.

-         The authors must explain more about the boundary conditions of the wall models. Why those BCs were defined? (page 9, line 309)

-         In section 2-6, why did the authors need to implement experimental tests to determine the mechanical properties of AAC materials and grout? There is not enough information in scientific references (pages 7,8, section 2-6- )?

-         The novelty and aims of this study should be better explained in the Introduction section (page 3, lines 116-126).

-         More relevant references about blast loading and analysis of the structures should be reviewed and mentioned in the revised version (page 2, lines 83-88; page 3, lines 89-96).

-         How did the reference model been selected (page 8, lines 296,297)?

 

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

All my comments have been appropriately addressed in the revised manuscript. From the reviewer point of view, the manuscript is well improved and it is worthwhile to be published.