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2015 Vol.31, Issue 3
Tensile Strength Characteristics of Cement Paste Mixed with Fibers

섬유가 혼합된 시멘트 페이스트의 인장강도 특성에 관한 연구

Sung-Sik Park1*
,
Yaolong Hou2
박 성식1*
,
호우 야오롱2
1Associate Prof., Dept. of Civil Engrg., Kyungpook National Univ.
2Graduate Student, Dept. of Civil Engrg., Kyungpook National Univ.
1경북대학교 공과대학 토목공학과 부교수
2경북대학교 공과대학 건축토목공학부 토목공학전공 석사과정
*교신저자. *Corresponding Author. 
31 March 2015. pp. 5-16
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Abstract

The characteristics of tensile strength of fiber-reinforced grouting (cement paste) injected into rocks or soils were studied. A tensile strength of such materials utilized in civil engineering has been commonly tested by an indirect splitting tensile test (Brazilian test). In this study, a direct tensile testing method was developed with built-in cylinder inside a cylindrical specimen with 15 cm in diameter and 30 cm in height. The testing specimen was prepared with 0%, 0.5%, or 1% (by weight) of a PVA or steel fiber reinforced mortar. A specimen with 5 cm in diameter and 10 cm in height was also prepared and tested for the splitting tensile test. Each specimen was air cured for 7 days or 28 days before testing. The tensile strength of built-in cylinder test showed 96%-290% higher than that of splitting tensile test. The 3D finite element analyses on these tensile tests showed that the tensile strength from built-in cylinder test had was 3 times higher than that of splitting tensile test. It is similar to experimental result. As an amount of fiber increased from 0% to 1%, its tensile strength increased by 119%-190% or 23%-131% for 7 days or 28 days-cured specimens, respectively. As a curing period increased from 7 days to 28 days, its strength decreased. Most specimens reinforced with PVA fiber showed tensile strength 14%-38% higher than that of steel fiber reinforced specimens.

Keywords
Tensile strength
Built-in cylinder
Split tensile test
Grouting
Fiber

본 연구에서는 토사 또는 암반 틈새에 주입하는 그라우팅(시멘트 페이스트)에 섬유를 혼합할 경우 발생하는 인장강도의 특성을 연구하였다. 이와 같이 시멘트로 고결된 토목재료의 인장강도 평가에는 간접적인 방법으로 인장강도를 평가하는 쪼갬인장시험을 주로 사용하고 있다. 하지만, 본 연구에서는 강섬유 또는 PVA 섬유를 중량비로 0%, 0.5%, 또는 1% 혼합한 시멘트 페이스트 내에 유압 실린더를 내장한 직경 15cm, 높이 30cm의 공시체를 제작한 다음 공시체 내부에서 직접 인장력을 가하는 직접인장시험법을 개발하였다. 또한 동일한 재료로 직경 5cm, 높이 10cm 공시체를 만들어 쪼갬인장시험을 실시하여 인장강도 시험방법에 따른 시멘트 페이스트의 인장강도를 비교, 평가하였다. 각각의 공시체는 대기 중에서 7일 또는 28일 양생한 다음 인장시험을 실시하였다. 시험방법에 따른 인장강도는 내장형 실린더를 이용한 직접인장시험법이 쪼갬인장시험법 보다 96%-290% 정도 높은 값을 보였다. 한편 두 종류의 인장시험법에 대한 3차원 유한요소해석을 실시하였으며, 실험 결과와 유사하게 내장형 실린더 인장시험법이 3배 정도 높은 인장강도를 보였다. 섬유 혼합량이 1%까지 증가함에 따라 인장강도는 시험방법에 관계없이 7일 양생한 공시체는 119%-190%, 28일 양생한 공시체는 23%-131%까지 증가하였으며, 양생일수가 7일에서 28일로 증가함에 따라 인장강도는 대부분 감소하는 경향을 보였다. 대부분의 경우 강섬유가 포함된 경우보다 PVA 섬유가 포함된 경우에 약 14%-38% 정도 높은 인장강도를 보였다.

References
1
1.Akkaya, Y., Picka, J., and Shah, S. P. (2000), “Spatial Distribution of Aligned Short Fibers in Cement Composites”, Journal of Materials in Civil Engineering, Vol.12(3), pp.272-279.
2
2.Altun, F., Haktanir, T., and Ari, K. (2007), “Effects of Steel Fiber Addition on Mechanical Properties of Concrete and RC Beams”, Construction and Building Materials, 21, pp.654-661.
3
3.Choi, S.-M. (2002), “Polyvinyl Alcohol Fibers: Introduction and Manufacturing Technology”, Fiber technology and industry, Vol.6, No.1/2, pp.83-95.
4
4.Dawood, E. T. and Ramli, M. (2010), “Development of High Strength Flowable Mortar with Hybrid Fiber”, Construction and Building Materials, 24, pp.1043-1050.
5
5.Itasca Consulting Group (2013), PLAXIS3D .
6
6.Johnson, H. D. (1981), “Diametric Disc and Standard Tensile Test Correlation Study”, Amarillo: Mason and Hanger-Silas Mason Co, Inc., Amarillo, TX (USA), MHSMP-81-22[R].
7
7.Kang, S. T., Kim, Y. Y., Lee, B. Y., and Kim, J. K. (2008), “Fiber Orientation Impacts on the Flexural Behavior of Steel Fiber Reinforced High Strength Concrete”, Journal of the Korea Concrete Institute, Vol.20(6), pp.731-739.
8
8.Kim, J. and Kim, D. Y. (2000), “A Study on the Flextural Toughness Evaluation Method of Steel Fiber Reinforced Shotcrete”, Tunnel & Underground, Vol.10, pp.196-210.
9
9.Krishna Rao, M. V., Rathish Kumar, P., and Srinivas, B. (2011), “Effect of Size and Shape on Specimen on Compressive Strength of Glass Fiber Reinforced Concrete (GFRC)”, Facta Universitatis, Vol.9, No.1, pp.1-9.
10
10.KS F 2423 (2001), Method of test for splitting tensile strength of concrete.
11
11.Ma, Li-lian (1993), “Measurement of Tensile Strain-stress Curve of High Energetic Explosive”, Chinese Journal of Energetic Materials, 1(3), pp.28-35.
12
12.Park, S.-S. and Kim, S.-J. (2013), “Effect of Steel-fiber Distribution on Flexural Strength and Toughness of Shotcrete-mimicked Concrete Specimen”, Journal of the Korean Geotechnical Society, Vol.29, No.6, pp.53-62.
13
13.Park, S.-S., Kim, K.-Y., Kim, C.-W., and Choi, H.-S. (2009), “Strength Variation of Cemented Sand due to Wetting”, Journal of the Korean Society of Civil Engineers, Vol.29, No.6C, pp.303-311.
14
14.Park, S.-S., Kim, Y.-S., and Lee, J.-C. (2007), “Unconfined Compressive Strength of Fiber-reinforced Cemented Sands by Fiber Reinforcement Form”, Journal of the Korean Geotechnical Society, Vol.23, No.8, pp.159-169.
15
15.Park, S.-S. and Lee, J.-W. (2014), “Study on the Direct Tensile Test for Cemented Soils Using a Built-in Cylinder”, Journal of the Korean Society of Civil Engineers, Vol.34, No.5, pp.1505-1516.
16
16.Patent No. 10-1327018 (2013), “Tension Test Apparatus Having Tension Test Device and Method for Tension Test”. (in Korean)
17
17.Plowman, J., Smith, W., and Sheriff, T. (1974), “Cores, Cubes and the Specific Strength of Concrete”, The Structural Engineer, 421-426.
18
18.Ravindrarajah, R. S. and Tam, C. T. (1984), “Flexural Strength of Steel Fibre Reinforced Concrete Beams”, The International Journal of Cement Composites and Lightweight Concrete, Vol.6(4), pp. 273-278.
19
19.Song, P. S., Hwang, S., and Sheu, B. C. (2005), “Strength Properties of Nylon-and Polypropylene-fiber-reinforced Concretes”, Cement and Concrete Research, 35, pp.1546-1550.
20
20.Zabihi, N. (2012), Effect of specimen size and shape on strength of concrete, Master of Science Thesis, Eastern Mediterranean University.
Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 31
  • No :3
  • Pages :5-16
  • Received Date : 2014-10-28
  • Revised Date : 2015-01-18
  • Accepted Date : 2015-03-06
  • DOI :https://doi.org/10.7843/kgs.2015.31.3.5
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