Modification Model of Glued-In Rods Splice Connection Using Statistical Analysis for Mengkulang Glulam Timber

Round 1

Reviewer 1 Report

Modification model of Glued-In Rods Splice Connection using Statistical Analysis for Mengkulang Glulam Timber

 

Strengthening elements of wooden structures with steel rods is an interesting way to increase their strength without having to increase their cross-section. However, the testing of such composites requires the use of full-size samples, which limits the possibility of easily creating, for example, many dimensional combinations of such elements. The ability to "predict" (calculate) the properties of such materials based on their easy-to-test features is a desirable direction of research of significant utilitarian importance. In this context, the article should be considered interesting and valuable. Nevertheless, the authors should supplement the presented methodology with a more detailed description of the material tested, the tests carried out, and the description of the results obtained, in particular:

·       there is only information that the research concerns Mengkulang Glulam Timber, there is no information about the density of the material, its moisture content. The research shows that these properties have been tested, but it is not described in the methodology.

·       lack of characteristics of the glue that was used to stick the bars and gluing parameters, how the glue thickness was tested.

·       no information on the method of destruction of the joints during the pull-out test, did the destruction occur in the wood or in the glue joint?

·       no description of the units on the axes of the graphs in figure 3 and figure 4.

·       The rearranged graphs in figures 3 and 4 make it difficult to compare them. For example, what does the moisture content value from 0.00005 to 0.00015 mean in the graphs in figure 3, or the value of glue thickness from 0.00005 to 0.00015? In figure 4, the moisture content values range from 10 to 20 and the glue thickness from 0 to 200. Probably some graphs are incorrectly labeled.

Taking into account the above remarks, the article requires a minor revision.

Author Response

Strengthening elements of wooden structures with steel rods is an interesting way to increase their strength without having to increase their cross-section. However, the testing of such composites requires the use of full-size samples, which limits the possibility of easily creating, for example, many dimensional combinations of such elements. The ability to "predict" (calculate) the properties of such materials based on their easy-to-test features is a desirable direction of research of significant utilitarian importance. In this context, the article should be considered interesting and valuable. Nevertheless, the authors should supplement the presented methodology with a more detailed description of the material tested, the tests carried out, and the description of the results obtained, in particular:

Answer -Method pull-out – detailed description of the material tested, has been presented from lines 93 to 130 in the manuscript.

      There is only information that the research concerns Mengkulang Glulam Timber, there is no information about the density of the material, its moisture content. The research shows that these properties have been tested, but it is not described in the methodology.

Answer-The information for density and MC has been added in lines 131 to 142 and 256 to 260.

Lack of characteristics of the glue that was used to stick the bars and gluing parameters, how the glue thickness was tested.

Answer- Tensile test for glue, was used to find the glue characteristics in lines 143 to 153 and 261 to 273..

no information on the method of destruction of the joints during the pull-out test, did the destruction occur in the wood or in the glue joint?

Answer-Information has been added in lines 275 to 286.

no description of the units on the axes of the graphs in figure 3 and figure 4.The rearranged graphs in figures 3 and 4 make it difficult to compare them. For example, what does the moisture content value from 0.00005 to 0.00015 mean in the graphs in figure 3, or the value of glue thickness from 0.00005 to 0.00015? In figure 4, the moisture content values range from 10 to 20 and the glue thickness from 0 to 200. Probably some graphs are incorrectly labeled.

Answer- As requested by the second reviewer, Figure 3 and Figure 4 have been deleted, accordingly.

Taking into account the above remarks, the article requires a minor revision.

 

Reviewer 2 Report

Comments for author File: Comments.docx

Author Response

Forests-2190988

The authors have contributed a good research article on “Modification model of Glued-In Rods Splice Connection using 2 Statistical Analysis for Mengkulang Glulam Timber”. There is a major correction required before it can be published. Following are the comments:

1. Authors should include statistical analysis techniques used by other researchers in the introduction section.

• Answer: The statistical analysis techniques were used by Cohen and Aiken., 2003 as shown in line 89 to 90.

1. Line 108: Is there any particular reason to take 107 data timber block specimens?

• Answer: The total of 107 timber specimens is tabulated in Table 1. The specimens prepared for both PR0⁰ and PR90⁰ were 54 nos. However, during the preparation of the samples, one of the samples for PR0⁰ was damaged during the test.

 

1. Kindly use a clear image in Fig. 2.

-Changed accordingly.

1. Table 2: The table is not clear. Notify the symbols and terms used.

• Answer: Table 2 has been adjusted accordingly. The related symbols and terms used in this study as mentioned in Equation 2 (line 180 to 189).

1. Section 2 needs to be shortened. There is no need for Fig. 3 and Fig. 4, it can be explained in sentences.

• Done accordingly.

1. Kindly rectify lines 195 and 236.

• Rectified accordingly.

1. Kindly present the equation in better form in Table 5.

• Revised accordingly.

1. In the result section authors have made a model and validated a model. But there is no proper justification for the findings mentioned in the result. Please add justification for the findings.

• Answer: From the validated model these findings show the equations are suitable to predict pull-out tests for 12, 16 & 20 mm for Mengkulang Glulam Timber. This sentence in lines 336 and 337 has been added to further justify the finding.

1. Conclusion can be rewritten by mentioning the proper application of the model developed by the authors.

• Answer: These models can be used to predict the pull-out for the strength of different dowel diameters, and different thicknesses of glue lines for parallel and perpendicular to the grain directions. It can be applied by the engineers to design glulam Mengkulang Pull-out connections and encourage the stakeholders in Malaysia’s timber industries to expend the use of tropical timber species.

 

 

Round 2

Reviewer 2 Report

NA