Friction and Cohesion Interface Shear Factors of Ultra-High-Performance Concrete (UHPC) Cast on Hardened Conventional Concrete

Round 1

Reviewer 1 Report

This work deals with the experimental and analytical investigation on Ultra-High-Perfor-mance Concrete (UHPC) cast on hardened conventional concrete, with the aim to find some factors to foresee their properties (e.g. interfacial shear resistance). The development of friction and cohesion factors was carried out by mean of several tests, such as the push-off shear tests and slant shear tests to have details about the surface texture, interface reinforcement ratio, compressive strength and fiber presence.

Overall, I found this paper very interesting and this topic falls within the scope of the journal. It is well written and conducted with scientific methodology. It can be accepted for publication after these minor revisions:

1.The structure of the paper is not clear. There are many paragraphs and subparagraphs. It is strongly recommended to merge together some paragraphs and to make the discussion more clear and easy to follow.

2.The methodological and experimental details can be inserted together in the “methods” section.

3.Some findings should be reported in the abstract.

4.Explain better the difference between high and low roughening.

5.Enrich the conclusion with the contribution of this study to technological applications and provide future perspectives.

only minor revisions 

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper presents a study on friction and cohesion interface shear factors of ultra-high-performance concrete (uhpc) cast on hardened conventional concrete

 

The following recommendations are proposed:

·         Please, rewrite the abstract. The reviewer believes this can be organized to give a wider audience a better understanding of the work performed.

·         Please, provide a flowchart of the research approach.

·         The conclusion can be separated from the discussion.

 

Major Concern:

What is the element of novelty of this paper?

Minor editing of English language required

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper presents the experimental and analytical investigations conducted to develop friction and cohesion factors of the shear friction theory for UHPC cast on hardened CC in composite sections. The topic is within scope of this journal and the contents could be interested to the readers. The authors need to clarify the following issues:

1.  A summary should be made in the review section. The novelty of this study can be stressed.

2. Figure 3a: what do the authors meant by 'no reinforcement'?  How is interface reinforcement ratio determined? Figure 2: please indicate the content of each part of the specimen.

3. Please provide details of shear key and deep grooved interface, and how the different types of surfaces were designed?

4. Please explain why aggregate exposed case has a higher shear strength?

5. More discussions on effects of interface reinforcement on failure, shear strength, slip and crack width can be made.

6. Please explain why the presence of fibers in UHPC does not have significant effect on the interface shear resistance of CC-UHPC.

7. How was the proposed factor proposed and validated?

English can be improved by proof reading. Please avoid repeating information in the text.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The paper in current form can be accepted.

Minor editing of English language required