A State-of-the-Art Review on the Incorporation of Recycled Concrete Aggregates in Geopolymer Concrete

Round 1

Reviewer 1 Report

This paper comprehensively studied the properties of geopolymer concrete incorporating with RCA. Tons of reference reviews provide a good description from RCA treatment, RCA mixing design and geopolymer concrete properties. However, before publishing it online, there are still several points must be improved:

1.      The writings of entire manuscript need polish and check.

2.      Line 135 – 136: The reviewer has a doubt on this conclusion that I agree the crushed aggregate has a rougher surface, but the surface usually contains the dust and old mortar, and these particles can block to form a strong bond strength between RCA and cement paste. Thus, the reviewer requires the authors to provide more convincible evidence and explanation on this conclusion. 

3.      Figure 5: typo on the label of x-axis.

4.      Figure 6: It is impressive to see the authors collect these data points from so many references; however, the reviewer has a question: how do you know if these samples from different papers adopt the same mixing design except the RCA content % and use the similar materials? If not, there is no meaning to compare the compressive strength with different RCA content %.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Author, 

The paper presents the rich state-of the art with strong backgroud, well described methodology and properly analysed. 

I do not have a major remarks to your work. 

I this it is worthy to publish the paper after following minor corrections:

2.1 - the paragraph describes rather geopolymer paste than concrete

Figure 2: "Records excluded:

(1) not being related to structural application

of GC, and RCA are not used as the

aggregates" - no "n" given

Table 1, Table 2, Table A1 - it would be more clear and easy to follow the table if it is sorted by the number of reference

Figure 4 - the additives shall contain references

Figure 5 - references shall be included

Figure 6, Figure 7, Figure 8, Figure 9, Figure 10, Figure 11, Figure 13 - numbers of references shall be included

4.3.2 - change: workability to Workability

Thank you!

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

The conclusion may need to be categorized to show the contribution. Although the total suggestions are enough to give a complete view of the topic of this study, it still need to be more organized.   

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The reviewer is satisfied with the revisions and agree to publish.