Browse > Article
http://dx.doi.org/10.14481/jkges.2022.23.9.5

A Study on Mechanical Properties and Applicability of CNT-Mixed Grout  

Kim, Seunghyun (Department of Civil and Environmental Engineering, Konkuk University)
Kim, Kanghyun (Department of Civil and Environmental Engineering, Konkuk University)
Shin, Jongho (Department of Civil and Environmental Engineering, Konkuk University)
Publication Information
Journal of the Korean GEO-environmental Society / v.23, no.9, 2022 , pp. 5-16 More about this Journal
Abstract
In recent years due to the development of urban and underground space, the number of ground disasters is increasing, and it is also leading to social problems. To solve the problem, a grouting method is generally used. However, the grouting method has material (grout) limitations in permeability, gelation properties and tensile resistance. Therefore, research on grout materials mixed with fibers is actively carried out to improve the problems. However, in the actual ground injection process, many difficulties have been faced causing the blockage of the inlet port and the injection tube. In this study, 'CNT-mixed grout material' was developed using CNT powder that can reinforce the tensile strength of soils. The uniaxial compressive and tensile strength tests were performed to obtain the optimal content and mechanical properties of the CNT Powder-mixed grout. It was found that the optimal CNT powder content is 0.5% that gives the average maximum strength. A one-dimensional injection test and the bulb formation test were carried out, and it was identified that the injection rate and bulb form could be controlled by pressure and mixing ratio. Field application of the CNT-Mixed grout is simulated using numerical analysis of slopes, foundations, and tunnels reinforced in several types. The positive effect of reducing plastic ranges and settlements was confirmed.
Keywords
CNT-Mixed grout; Reinforcement; Tensile strength; Injection;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
연도 인용수 순위
1 Yang, H. C., Kim, K. H., Kim, B. S., Kim, S. H. and Kim, Y. S. (2012), Grouting Environmental Engineering, Goomibook, pp. 174~180.
2 Ha, S. J., Kang, S. T. and Lee, J. H. (2015), Strength of CNT cement composites with different types of surfactants and doses, Journal of the Korea institute for structural maintenance and inspection, 19(2), pp. 99~107 (In Korean).   DOI
3 Kim, S. M. (2004), Tunnel grouting design and construction, Korea Resources Corporation (In Korean).
4 Korean Society for Rock Mechanics and Rock Enineering, (2006), Standard test method for indirect tensile strength of rock by the Brazilian test (In Korean).
5 Korea Rural Community Corporation (2018), Basic treatment (grouting) construction specification standard (draft) (In Korean).
6 Li, G. Y., Wang, P. M. and Zhao, X. (2005), Mechanical behavior and microstructure of cement composites incorporating surface-treated multi-walled carbon nanotubes, Carbon, 43(6), pp. 1239~1245.   DOI
7 Manzur, T., Yazdani, N. and Emon, M. A. B. (2014), Effect of carbon nanotube size on compressive strengths of nanotube reinforced cementitious composites, Journal of Materials, pp. 1~8.
8 MOLIT (2016), Ground grouting (KCS 11 30 45 : 2016) standard specification (In Korean).
9 Paul, B. (1961), A modification of the Coulomb-Mohr theory offracture, Journal of Applied Mechanics, 28(2), pp. 259~268.   DOI
10 ASTM D2166 (2014), Standard Test Method for Unconfined Compressive Strength of Cohesive Soil, USA.
11 Chaipanich, A., Nochaiya, T., Wongkeo, W. and Torkittikul, P. (2010), Compressive strength and microstructure of carbon nanotubes-fly ash cement composites. Materials Science and Engineering: A, 527(4~5), pp. 1063~1067.   DOI
12 Mair, R. J. and Taylor, R. N. (1997), Theme lecture: Bored tunnelling in the urban environment, In Proceedings of the fourteenth international conference on soil mechanics and foundation engineering. Rotterdam, pp. 2353~2385.
13 KS F 2405 (2017), Standard Test Method for Compressive Strength of Concrete (In Korean).
14 ASTM D3967 (2016), Standard Test Method for Splitting Tensile Strength of Intact Rock Core Specimens, USA.
15 Seo, J. W., Lee, I. M., Kim, B. K. and Kwon, Y. S. (2018), Behavior of cement-based permeation grouting in cohesionless soil considering clogging phenomena, Journal of Korean Tunnelling and Underground Space Association, 20(2), pp. 485~500 (In Korean).   DOI
16 Collins, F., Lambert, J. and Duan, W. H. (2012), The influences of admixtures on the dispersion, workability, and strength of carbon nanotube-OPC paste mixtures. Cement and Concrete Composites, 34(2), pp. 201~207.   DOI
17 Kim, K. H. (2021), Eco-friendly Earth Reinforcing Material using Biopolymer and Natural Fiber, PHD thesis, Konkuk University, pp. 4 (In Korean).