Performance and Verification of High-Modulus Asphalt Modified by Styrene-Butadiene-Styrene Block Copolymer (SBS) and Rock Asphalt
Round 1
Reviewer 1 Report
Thank you very much for doing and communicating a good piece of research. I have highlighted and suggested the text and points which could be improved to make this article even better. See the attachment. The explanation of the method and results can be improved to make it more cohesive. I wish you good luck with its possible publication.
Comments for author File: 
Comments.pdf
Author Response
Special thanks to you for your good comments. We have carefully revised the manuscript, and the paper was also re-scrutinized to improve the English. Our responses are in PDF, and we amended the relevant part in revised manuscript and the changes below are noted in red words in the article.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments for author File: Comments.pdf
Author Response
Special thanks to you for your good comments. We have carefully revised the manuscript, and the paper was also re-scrutinized to improve the English. Our responses are as follows, and we amended the relevant part in revised manuscript and the changes below are noted in red words in the article.
1.The information’s provided in section 2.3 are not sufficient. Testing method should be rewritten with proper information.
Response: Thank you for your suggestion. The experimental methods used in the paper have been supplemented.
(1) Penetration, softening point, ductility and viscosity tests
Penetration is one of the main quality control indexes of asphalt. The relative hardness and consistency of asphalt and its ability to resist shear failure can be characterized. The test is carried out according to the test specification (JTG E20-2011) [26]. A 100g standard cone was sunk vertically into a bitumen sample insulated at 25 ° C within 5 seconds, and the depth was recorded in 1/10mm units.
Softening point refers to the temperature measured when the asphalt specimen is softened and sagged by heat, which represents the temperature stability of asphalt. The test is carried out according to the test specification (JTG E20-2011) [26]. The asphalt sample in the metal ring of prescribed size was placed in 5℃ water or 32.5℃ glycerol, and heated at a rate of 5±0.5℃/min until the steel ball sank to the prescribed distance (25.4mm). The temperature was recorded and expressed in ℃.
Ductility is an important index to evaluate the plasticity of asphalt. The test is carried out according to the test specification (JTG E20-2011) [26]. The asphalt was poured into a figure-8 standard specimen, and the specimen was drawn to fracture at a speed of 50mm/min under the corresponding test temperature (5℃,10℃,15℃ or 25℃). The length at this time was recorded and expressed as cm.
Viscosity is an index to characterize the viscosity of asphalt, the main basis for the classification of modern asphalt, and a main control index for the production and construction of asphalt mixture. There are many viscosity indicators, and 135℃ kinematic viscosity is selected to study in this paper. The kinematic viscosity at 135℃ is often measured by a capillary viscosity meter according to the test specification (JTG E20-2011) [26].
(2) Segregation softening point test
Segregation softening point test is usually used to evaluate the thermal storage stability of SBS modified asphalt according to Chinese standard JTG E20-2011[26]. The separation tube containing about 50g of asphalt was sealed and put in an oven at 163 ℃ ± 5 ℃ for 48 h ± 1 h, and then was moved to the freezer for at least 4 hours. After the asphalt is solidified, it is taken out and divided into three equal parts, and the upper and lower softening points are measured according to the softening point test method (T0606), and the difference is taken. When the value is less than 2.5 ℃, it is considered that the SBS modified asphalt segregation is qualified.
(3) Dynamic shear rheometer (DSR)
The dynamic shear rheometer (DSR) is usually used to evaluate the high temperature stability of asphalt binder. According to Chinese standard JTG E20-2011[26], a fully automatic dynamic shear rheometer was used to determine the dynamic shear modulus and phase angle of asphalt. The instrument applies periodic sinusoidal shear stress to asphalt samples through the axis of rotation. The asphalt sample is placed between two 25mm plates, one plate is fixed, the other plate is rotated around the central axis at a speed of 10rad/s. It goes through the A-B-A-C-A cycle. When the stress (strain) is applied to the sample, DSR can calculate the strain (stress) response generated by the sample, and the complex shear modulus can be calculated from the stress and the corresponding strain.
(4) Bending beam rheometer (BBR)
Bending Beam Rheometer (BBR) is usually used to evaluate the low temperature performance of asphalt materials. According to Chinese standard JTG E20-2011[26], a fully automatic bending beam rheological tester was used to measure the flexural creep stiffness modulus S and creep rate m. The bending beam rheometer applies loads to asphalt samples through load sensors and records deflection changes over time. The instrument can automatically collect the creep stiffness modulus S of sample at 8s, 15s, 30s, 60s, 120s and 240s, and calculate the value of creep rate m when the test is carried out at the test temperature. The asphalt should be kept warm in absolute ethanol at constant temperature before the start of the test. Taking into account the low temperature climate in cold regions, the test temperature is selected as -12°C and -18°C.The S and m values with the load acting time of 60s are taken in the test.
(5) Pneumatic rheological rebound test
The maximum creep deformation when loaded and the ability to recover from deformation when unloaded are unique properties of each thermoplastic material. The LTI-210 asphalt quality rapid testing equipment can quickly evaluate the mechanical response and road performance of asphalt materials at a certain temperature. It mainly uses nitrogen loading technology to load asphalt specimens at 25℃ in a circular area for a period of time. The laser measurement system of the equipment measures and records the deformation (displacement) of the loading center. After the loading is finished, the deformation of asphalt materials begins to recover. The creep and creep recovery ability of asphalt under single stress or multiple stress conditions can be measured.
2.Rock-well hardness test result is missing; authors need to include this result.
Response: In Rockwell hardness test, a standard indenter is used to apply test force (initial test force F0 and total test force F0 + F1) to the surface of the tested material twice. Under the action of test force, the indenter is pressed into the surface of the sample, and the hardness value is determined by the depth of indentation plastic deformation, with 0.002mm as a hardness unit. Rockwell hardness test is suitable for the hardness test of metal materials, not for the hardness test of asphalt materials studied in this paper. For the hardness test of asphalt materials, the standard specification requires the penetration test of asphalt, which is the data analysis of Fig.1 (b) in Section 3.1 of this paper.
Reviewer 3 Report
Review
Title: Performance and verification of high modulus asphalt modified by SBS and rock asphalt
Authors: Yuxin Li, Xiangpeng Yan, Jianmin Guo, Wenjuan Wu, Wencheng Shi, Qinsheng Xu, Zhengjun Ji
Submitted to section: Surface Characterization, Deposition and Modification,
Special Issue: Asphalt Pavement Materials and Surface
- Several references are not properly given and some checking of all other references should be done!
- Presentation of results should be more rigorous. Discussion seem as appropriate.
- Line 68: Correct: “For example, bulgis, mwtjaronge, SAA disasmita and mhustim [21]..” to “For example, Bulgis et al. [21]….”
Correct, also, the reference 21 to:
[21] Bulgis, M. W. Tjaronge, S. A. Adisasmita and M. Hustim. Effect of Buton Granular Asphalt (BGA) on compressive stress-strain behavior of asphalt emulsion mixture. IOP Conf. Series: Materials Science and Engineering 271 (2017) 012069. https://doi.org/10.1088/1757-899X/271/1/012069
- Line 69 and 71: Correct: “butun rock asphalt” to “Buton rock asphalt”
- Line 72: Correct: “Nyoman suaryana [22] et al. Studied..” to
“Suaryana [22] studied….”
Correct, also, the reference [22]: [22] Nyoman Suaryana. Performance evaluation of stone matrix asphalt using indonesian natural rock asphalt as stabilizer[J]. International Journal of Pavement Research and Technology,2016,9:387-392.
to
[22] N. Suaryana. Performance evaluation of stone matrix asphalt using indonesian natural rock asphalt as stabilizer. Int. J. Pavement Res. Technol. 9 (5) (2016) 387-392. https://doi.org/10.1016/j.ijprt.2016.09.007
- Correct “Ruixia Li [23] and others used…” to “Li et al. [23] used…”
Correct, also, reference [23] to:
[23] R. X. Li, P. Karki, P. Hao, A. Bhasin. Rheological and low temperature properties of asphalt composites containing rock asphalts. Constr. Build. Mater. 96 (2015) 47-54. https://doi.org/10.1016/j.conbuildmat.2015.07.150
- Line 80: Correct
“Huang Gang, he Zhaoyi, Zhang Zhengguo, Yang Yang [24] and others have systematically..” to
“Huang et al. have systematically….”
Correct, also, the reference [24] to:
[24] G. Huang, Zh. He, Zh. Zhang, Y. Yang. Research on properties of rutted rock asphalt modified mixture. J. China Foreign Highway 2009 (3) 187-192.
- Correct “Li Ruixia Hao Peiwen, Wang Chun [25] and others have compared…”
to
”Li et al. have compared…”
The reference [25] as given is erroneous. The proper reference is:
[25] R. X. Li, P. W. Hao, Ch. Wang. Performance Evaluation of BRA Modified Asphalt Based on Analysis of Rheological Property. Adv. Mater. Res. 374-377 (2012) 1385-1390. https://doi.org/10.4028/www.scientific.net/AMR.374-377.1385
- Line 107, Table 2: Only the basic index of SBS modifier is given, that is not enough, more data are needed (MFR, softening point,…), or at least the commercial type!
- Assumed that (in Table 2) SBS is not “Line type” but “linear type”!
- The following pairs of variables have p-values below 0.05 that indicate statistically significant non-zero correlations at the 95.0% confidence level:
A. SBS modifier/%: and softening point, oC, and penetration, 0.01 mm, and 10 oC ductility, cm, and and 135 oC kinematic viscosity, Pa.sand softening point difference, oC, and -12 oC creep rate m-value, and Final creep deformation /mm, and Creep recovery rate, %, and Maximum creep deformation /mm;
B. Rock asphalt powder/%: and softening point, oC, and penetration, 0.01 mm, and 10 oC ductility, cm, and -12 oC stiffness modulus, Mpa, and -18 oC stiffness modulus, Mpa, and -12 oC creep rate m-value, and -18 oC creep rate m-value and Final creep deformation /mm, and Creep recovery rate, %, and Maximum creep deformation /mm;
Properties are also correlated, and this makes some experimental measurements redundant:
a) softening point, oC and penetration, 0.01 mm, and 135 oC kinematic viscosity, Pa.s, and -12 oC stiffness modulus, Mpa
b) penetration, 0.01 mm and 135 oC kinematic viscosity, Pa.s, and -12 oC stiffness modulus, Mpa
c) 10 oC ductility, cm and softening point difference, oC, and -12 oC stiffness modulus, Mpa, and -18 oC stiffness modulus, Mpa, and -12 oC creep rate m-value, and -18 oC creep rate m-value
d) softening point difference, oC and -12 oC creep rate m-value, and -18 oC creep rate m-value
e) -12 oC stiffness modulus, Mpa and -18 oC stiffness modulus, Mpa, and -12 oC creep rate m-value, and -18 oC creep rate m-value
f) -18 oC stiffness modulus, Mpa and -12 oC creep rate m-value, and -18 oC creep rate m-value
g) -12 oC creep rate m-value and -18 oC creep rate m-value
- In Chapter 3.1 Penetration, softening point, ductility and viscosity index, results are presented as chart graphs. However, due to mixture design as given in Table 4. The modifier blending scheme, multivariate analysis would seem more plausible!
- Multivariate analysis then gives SBS modifier and Rock asphalt powder component effects:
Softening point, oC= 49.48 +2.672 ´ SBS modifier/% +1.576 ´ Rock asphalt powder/%
R-squared (adjusted for d. f.) = 96.81 percent
Figure 1
penetration, 0.01 mm = 44.22 -1.809 ´SBS modifier/% -1.077 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 95.03 percent
Figure 2
10 oC ductility, cm = 21.83 +2.760 ´SBS modifier/% -1.693 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 76.31 percent
Figure 3
135 oC kinematic viscosity, Pa.s= 0.02199 + 0.4527 ´SBS modifier/% +0.1218 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 84.81 percent
Figure 4
softening point difference, oC = -0.052 + 0.455 ´SBS modifier/%
R-squared (adjusted for d.f.) = 29.80 percent
Figure 5
-12 oC stiffness modulus, MPa = 176.06 - 7.117 ´SBS modifier/% + 20.126 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 94.84 percent
Figure 6
-18 oC stiffness modulus, MPa = 330.13 - 8.420 ´SBS modifier/% + 10.62 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 85.3199 percent
Figure 7
-12 oC creep rate m-value = 0.3219 + 0.0102 ´SBS modifier/% - 0.00705 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 95.64 percent
Figure 8
-18 oC creep rate m-value = 0.2500 + 0.00975 ´SBS modifier/% - 0.00806 ´Rock asphal powder/%
R-squared (adjusted for d.f.) = 91.92 percent
Figure 9
Final creep deformation /mm = -0.06797 + 0.0073 ´SBS modifier/% + 0.0037 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 85.58 percent
Figure 10
Creep recovery rate, % = 15.62 + 3.49 ´SBS modifier/% + 2.54 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 96.23 percent
Figure 11
Maximum creep deformation /mm = -0.086054 + 0.008562 ´SBS modifier/% + 0.00418197 ´Rock asphalt powder/%
R-squared (adjusted for d.f.) = 87.56 percent
Figure 12
- Or something like 3D graphics:
Figure 13
Figure 14
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Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Figure 22
Figure 23
Figure 24
- Figure 5. is rather confusing, overcrowded. At least, split in 2 separate figures!
- Figure 6. Creep deformation recovery rate diagram of modified asphalt and Figure 7. PG classification diagram of modified asphalt with different dosages. are not necessary as the data are given in the Table 4. The creep deformation and recovery rate of different asphalt samples.
Comments for author File: Comments.pdf
Author Response
Special thanks to you for your good comments. We have carefully revised the manuscript, and the paper was also re-scrutinized to improve the English. Our responses are as follows, and we amended the relevant part in revised manuscript and the changes below are noted in red words in the article.
1.Several references are not properly given and some checking of all other references should be done!
Response: The errors in the references in the article have been corrected.
- Presentation of results should be more rigorous. Discussion seem as appropriate.
Response: Thank you for your suggestion. We have.
3-8. Response: The errors in the references in the article have been corrected.
- Line 107, Table 2: Only the basic index of SBS modifier is given, that is not enough, more data are needed (MFR, softening point,…), or at least the commercial type!
Response: Thank you for your suggestion. In the article, more information about SBS modifier was added in Table 2.
- Assumed that (in Table 2) SBS is not “Line type” but “linear type”!
Response: The error in Table 2 has been corrected.
- In Chapter 3.1 Penetration, softening point, ductility and viscosity index, results are presented as chart graphs. However, due to mixture design as given in Table 4. The modifier blending scheme, multivariate analysis would seem more plausible!
Response: Thank you for your good suggestion. The multivariate analysis was added in 3.3.4.
- In Chapter 3.1 Penetration, softening point, ductility and viscosity index, results are presented as chart graphs. However, due to mixture design as given in Table 4. The modifier blending scheme, multivariate analysis would seem more plausible!
Response: Thank you for your good suggestion. The multivariate analysis was added in 3.3.4.
13-14. Response: Thank you for your good suggestion. The multivariate analysis was added in 3.3.4.
- Figure 5. is rather confusing, overcrowded. At least, split in 2 separate figures!
Response: Figure.5 has been split into 2 separate figures.
- Figure 6. Creep deformation recovery rate diagram of modified asphalt and Figure 7. PG classification diagram of modified asphalt with different dosages. are not necessary as the data are given in the Table 4. The creep deformation and recovery rate of different asphalt samples.
Response: Figure 6 and Figure 7 have been deleted from the paper.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Properties mainly depend on the composition: SBS modifier/%: and Rock asphalt powder/%. Properties are also inter-correlated, and this makes some experimental measurements redundant. You may further study these effects. Best regards
