Injection Characteristics Evaluation of Conductive Grout Material According to Carbon Fiber Mixing Ratio

Hyojun Choi; Wanjei Cho; Hyungseok Heo; Teawan Bang; Chanyoung Yune

doi:10.14481/jkges.2023.24.1.15

All Issue

2023 Vol.24, Issue 1 Preview Page Next Page

Injection Characteristics Evaluation of Conductive Grout Material According to Carbon Fiber Mixing Ratio 탄소섬유 배합비에 따른 전도성 그라우트 재료의 주입특성평가

1 January 2023. pp. 15-23

PDF XML

Abstract

The grouting method is a method of construction for the purpose of waterproofing and reinforcing soft ground. When grout is injected into the ground, there are various types of penetration and diffusion of grout depending on the shape of the ground, the size of soil, the porosity, and the presence or absence of groundwater. the current situation. Therefore, in this study, to investigate the penetration performance of the grouting to conductive material, laboratory tests were performed on the addition of the conductive material. In the injection test, 0%, 3%, and 5% of the mixed water were added as conductive materials to the grout, and the original ground condition was composed of various types of ground composed of gravel and silica sand. Conductive grout is injected by pressure into the model ground using a dedicated injection device, and the injection time (t), pressure (p), flow rate (v) and injection amount (q) are measured, and the hardened body injected in the model ground is collected. Penetration performance was evaluated. In the results of the grout injection experiment, the amount of conductive material used and the grout injection rate showed an inverse relationship, and it was confirmed that the penetration pattern was changed according to the size of the soil particles in the model ground. The grout containing the conductive material has relatively good penetration into the ground and excellent strength and durability of the hardened body, so it was judged that it could be used as an additive for measuring the penetration range of the grout.

Keywords

Poor ground

Grouting

Micro-cement

Carbon fiber

Injection test

그라우팅 공법은 연약지반의 차수 및 보강을 목적으로 시공되는 공법이다. 그라우트가 지반 내에 주입될 때, 지반을 구성하는 지반의 형태, 토립자의 크기, 공극율 및 지하수의 유무에 따라 그라우트가 침투 및 확산하는 형태가 다양하게 나타나고 있으나, 그라우팅 설계 시에는 이러한 요인을 적용하기 어려운 실정이다. 따라서, 본 연구에서는 전도성 재료를 함유한 그라우트를 지반 내로 주입하는데 있어서 전도성 재료 첨가에 따른 그라우트의 침투 성능을 파악하기 위하여 실내시험을 수행하였다. 주입시험에서는 전도성 재료를 혼합수의 0%, 3% 및 5%를 그라우트에 첨가하고, 원지반 조건을 자갈과 규사로 구성된 다양한 지반으로 조성하였다. 전도성 그라우트는 전용주입장치를 사용하여 모형지반 내로 압력에 의해 주입되면서 주입시간(t), 압력(p), 유속(v) 및 주입량(q)를 계측하고, 모형지반 내 주입된 경화체를 채취하여 침투성능을 평가하였다. 그라우트 주입실험 결과에서는 전도성 재료의 사용량과 그라우트 주입율은 역의 관계를 나타내었으며, 모형지반 토립자 크기에 따라 침투형태가 변화되는 것을 확인하였다. 전도성 재료를 함유한 그라우트는 지반 내 침투가 비교적 양호하고 경화체의 강도 및 내구성이 우수하여 그라우트의 침투범위 측정을 위한 첨가제로 사용하는 것이 가능하다고 판단하였다.

키워드

연약지반

그라우팅

마이크로시멘트

탄소섬유

주입시험

References

Cao, J. and Chung, D.D.L. (2001), Carbon fiber reinforced cement mortar improved by using acrylic dispersion as an admixture, Cement and Concrete Research, Vol. 31, Issue 11, pp. 1633~1637. 10.1016/S0008-8846(01)00599-3

Chen, B. and Liu, J. (2003), Effect of fibers on expansion of concrete with a large amount of high f-CaO fly ash, Cement and Concrete Research, Vol. 33, Issue 10, pp. 1549~1552. 10.1016/S0008-8846(03)00098-X

Choi, H. J., Cho, W. J., Hwang, B. S. and Yune, C. Y. (2020), Mechanical properties of cement grout including conductive materials, Korean Geo-Environmental Society, Vol. 21, No. 12, pp. 35~41 (In Korean). 10.52723/JKL.41.029

Choi, H. J., Cho, W. J. and Yune, C. Y. (2021), Characteristics evaluation of conductive grout material according to carbon fiber mixing ratio, Korean Geo-Environmental Society, Vol. 22, No. 12, pp. 15~24 (In Korean).

Graham, R. K., Huang, B., Shu, X. and Burdette, E.G. (2013), Laboratory evaluation of tensile strength and energy absorbing properties of cement mortar reinforced with micro- and meso-sized carbon fibers, Construction and Building Materials, Vol. 44, pp. 751~756. 10.1016/j.conbuildmat.2013.03.071

Heo, H. S. and Park, I. J. (2020), A Study on the Hardening Characteristics of Ground Injection Grout under Various Curing Conditions, Korean Geo-Environmental Society, Vol. 21, No. 11, pp. 11~20 (In Korean).

Jeon, W. W. (2021), Effects of applied stress, pore fluid types and concentrations on the eletrical conductivity of silica sand with varying amounts of graphite, Master's Thesis, Kyung Hee University (In Korean).

Kang, S. H., Choi, H. K., Park, C. S. and Roh, J. H. (2002), The emergence of cement-based accelerating agent ground injection materials, KSCE Journal of Civil Engineering, Vol. 50, No. 8, pp. 9~15.

Peyvandi, A., Soroushian, P., Balachandra, A. M. and Sobolev, K. (2013), Enhancement of the durability characteristics of concrete nanocomposite pipes with modified graphite nanoplatelets, Construction and Building Materials, Vol. 47, pp. 111~117. 10.1016/j.conbuildmat.2013.05.002

Shu, X., Graham, R. K., Huang, B. and Burdette, E. G. (2015), Hybrid effects of carbon fibers on mechanical properties of Portland cement mortar, Materials & Design, Vol. 65, pp. 1222~1228. 10.1016/j.matdes.2014.10.015

Information

Publisher :Korean Geo-Environmental Society
Publisher(Ko) :한국지반환경공학회
Journal Title :Journal of the Korean Geo-Environmental Society
Journal Title(Ko) :한국지반환경공학회 논문집
Volume : 24
No :1
Pages :15-23
Received Date : 2022-10-25
Revised Date : 2022-12-08
Accepted Date : 2022-12-27
DOI :https://doi.org/10.14481/jkges.2023.24.1.15

Journal of the Korean Geo-Environmental Society ISSN:1598-0820(Print) 2714-1233(Online) 한국지반환경공학회 논문집

All Issue