Preliminary Study of New Sustainable, Alkali-Activated Cements Using the Residual Fraction of the Glass Cullet Recycling as Precursor

Round 1

Reviewer 1 Report

It seems that the 4M NaOH concentration is the optimal value that led to the greatest compressive strength compared to the 1M and 6M concentrations. As 4M NaOH provides more chemical activators compared to the 1M concentration, the AAC achieved a higher compressive strength. But why did the 6M concentration yielded a lower compressive strength compared to the 4M concentration? Please elaborate.

English of this manuscript needs to be carefully edited and proofread. Some editorial comments are listed below:

Line 60: please make correction to “Check Republic”

Line 249: please change “A deep” to “An in-depth”

Line 252: please change “exhibit in Figure 6” to “exhibited in Figure 6”

Line 255: please change “it can be noticed higher values in the 4M and lower values in the 1M” to “it can noticed that samples with the 4M concentration have higher values while samples with the 1M concentration have lower values”

Line 267: change “showed” to “shown”

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

This study focused on the potential of CSP as a precursor to synthesize AAC. The concentration of the alkali activator (NaOH: 1M, 4M, and 8M) and the liquid-to-solid ratio (L/S) were tested in the formulation of the ACC. Generally speaking, this is a well-organized paper and can be of general interest to the readers of Applied Science. However, there are some problems the authors should look into.

1. The abstract contains a lengthy description of the background information which should be more brief. It is suggested that the authors add major experimental results/findings in the abstract.
2. The waste glass geopolymer is not a new topic. The authors should give more detailed literature review including the mechanical properties of waste glass geopolymer. (e.g., "Compressive strength and microstructure analysis of geopolymer paste using waste glass powder and fly ash. Journal of cleaner production, 172, pp.2892-2898.";"Strength, microstructure, efflorescence behavior and environmental impacts of waste glass geopolymers cured at ambient temperature. Journal of Cleaner Production, 252, p.119610." etc.)
3. The authors should make it clear why this is an innovative study in the last paragraph of introduction.
4. Based on the manuscript, "The molds were sealed in a plastic bag to minimize the moisture loss for 3 days at 40°C ± 1°C (relative humidity of 10% ± 5%) in a climate chamber." Why did the authors use such a low relative humidity condition to cure the geopolymer?
5. The compressive strength should be compared with those in previous studies.
6. More in-depth discussions should be made based on the experimental results. What's the relationship between the microstructure of geopolymer and the compressive strength?
7. The conclusion part is length. The authors should highlight the major experimental findings in this study and try to make make general conclusions

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have adequately address the reviewer's comments. A couple of more editorial comments:

Line 259: should it be Figure 5 instead of Figure 6?

Line 301: please change "when is compared to" to "when compared to"

Reviewer 2 Report

This paper has been revised based on the comments and should be ready for publication.