DOI QR코드

DOI QR Code

Quantitative Estimation of Joint Spacing for Concrete Slab to Prevent Cracking of Drying Shrinkage

건조수축에 따른 균열 방지를 위한 콘크리트 슬래브의 정량적 줄눈 간격 산정

  • 이수진 (건국대학교 사회환경시스템공학과) ;
  • 이회근 (삼성물산(주) 건설부문 기술연구센터 기반기술연구소) ;
  • 이승훈 (삼성물산(주) 건설부문 기술연구센터 기반기술연구소) ;
  • 원종필 (건국대학교 사회환경시스템공학과)
  • Received : 2010.12.02
  • Accepted : 2011.04.08
  • Published : 2011.06.30

Abstract

The installation of joint is to prevent random cracking due to drying shrinkage stress of concrete slab. However contraction joint spacing is empirically implemented into slab constructions without detail calculation based on quantitative criteria. In this study, shrinkage strain of concrete due to concrete shrinkage stress was measured to suggest joint spacing based on the study results. The test environmental conditions were applied temperature of $15^{\circ}C$ and relative humidity of 60%. The design compressive strength used was 30 MPa and 40 MPa, which are currently used in concrete slab designs. The drying shrinkage test result was applied to drying shrinkage models (ACI 209R, CEB MC 90, B3, GL 2000 and Sakata). The results showed that the most appropriate model was ACI 209R model. Based on the research findings, quantitative contraction joint spacing locations were calculated.

콘크리트 슬래브의 수축으로 인해 발생하는 응력에 의한 무분별한 균열을 억제하기 위해 줄눈을 설치한다. 그러나 설치된 줄눈의 간격은 구체적인 산출 근거나 정량적인 기준 없이 경험적으로 나누어지고 있다. 따라서 이 연구에서는 콘크리트 슬래브의 수축 응력에 의한 변형량을 측정하고 이에 따른 정량적인 평가 기준을 제시하고자 한다. 노출된 환경 조건은 온도 $15^{\circ}C$, 상대습도 60%를 적용하였다. 건조수축 실험은 현재 슬래브 설계에 많이 사용되는 설계 강도 30 MPa 및 40 MPa 배합을 사용하였고 그 결과를 기존 건조수축 모델에 적용하였다. 그 결과 ACI 209R 모델에 가장 일치하는 것으로 나타났으며 이를 바탕으로 콘크리트 슬래브의 정량적인 줄눈 간격을 산정하였다.

Keywords

References

  1. 한국콘크리트학회, 최신콘크리트공학, 기문당, 2005, 844 pp.
  2. 이홍재, "팽창줄눈 간격의 이론적 산정," 중앙대학교 건설대학원 석사논문, 1999.
  3. 한국콘크리트학회, 콘크리트구조설계기준 해설, 기문당, 2008, 523 pp.
  4. 한국도로공사, 도로설계요령, 2002.
  5. 국토해양부, 도로설계편람, 2000.
  6. ACI 224.3R-95, Joints in Concrete Construction, American Concrete Institute, ACI Committee 224, pp. 2-3.
  7. ACI 360R-06, Design of Slabs-on-Ground, ACI Committee 360, pp. 23-28.
  8. ACPA, Design and Construction of Joints for Concrete Streets, American Concrete Pavement Association, 1992, IS061.01P, pp. 1-12.
  9. ACI 302.1R-96, Guide for Concrete Floor and Slab Construction, ACI Committee 302, 10 pp.
  10. Bogemconcrete.com/Concrete-tips, Concrete Parking Area Construction.
  11. Bazant Z. P., "Prediction of Concrete Creep and Shrinkage: Past, Present and Future," Nuclear Engineering and Design, Vol. 203, 2001, pp. 27-38. https://doi.org/10.1016/S0029-5493(00)00299-5
  12. ACI 209R-92, Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structure, American Concrete Institute, ACI Committee 209, 6 pp.
  13. CEB-FIP Model Code 1990, Comite Euro International Du Beton, 1991, 57 pp.
  14. Bazant, Z. P. and Kim, J. K., "Improved Prediction Model for Time-Dependent Deformations of Concrete : Part 1-Shrinkage," Materials and Structures, Vol. 24, 1991, pp. 327-345. https://doi.org/10.1007/BF02472066
  15. Gardner, N. J. and Lockman, M. J., "Design Provisions for Drying Shrinkage and Creep of Normal Strength Concrete," ACI Materials Journal, Vol. 98, No. 2, 2001, pp. 159-167.
  16. Sakata, K., "Prediction of Concrete Creep and Shrinkage, Creep and Shrinkage of Concrete," Proceedings of the 5th International RILEM Symposium, London, UK, 1993, pp. 649-654.
  17. ACI 209.2R-08, Guide for Modeling and Calculating Shrinkage Shrinkage and Creep in Hardened Concrete, ACI Committee 209, 16 pp.
  18. McDonald, D. B. and Roper, H., Accuracy of Prediction Model for Shrinkage of Concrete, ACI Material Journal, Vol. 90, 1993, pp. 265-271.
  19. Akthem, Al-M. and Lam, J. P., "Statistical Evaluation of Shrinkage and Creep Models," ACI Material Journal, Vol. 102, No. 3, 2005, pp. 170-176.
  20. 전쌍순, 박태균, 황택진, 엄장섭, 진치섭, "콘크리트 크리 프와 건조수축의 CEB-FIP 모델코드와 ACI 코드의 비교," 부산대학교 생산기술연구소논문집, 61권, 2002, pp. 63-73.
  21. Bazant, Z. P. and Li, G. H., "Unbiased Statistical Comparison of Creep and Shrinkage Prediction Models," ACI Material Journal, Vol. 105, No. 6, 2008, pp. 610-622.
  22. ACI 308-81, Standard Practice for Curing Concrete, ACI Manual of Concrete Practice, Part 2, ACI Committee 308, 2001.
  23. Bazant, Z. P. and Xi, Y., "New Test Method to Separate Microcracking from Drying Creep: Curvature Creep at Equal Bending Moment and Various Axial Forces, Creep and Shrinkage of Concrete," Proceeding of the Fifth International RILEM Symposium, 1993, pp. 77-82.
  24. Miltenberger, M. A. and Attiogbe, E. K., "Shrinkage-Based Analysis for Control Joint Spacing in Slab on Ground," ACI Structural Journal, Vol. 99, No. 3, 2002, pp. 352-359.
  25. Tarr, S. M. and Farny, J. A., Concrete Floors on Ground, Portland Cement Association, 4th Edition, 2008, pp. 91-109.
  26. Merril, W. S., "Prevention and Control of Cracking in Reinforced Concrete Building," Engineering News-Record, Vol. 131, No. 23, 1943, pp. 91-93.
  27. Fintel, M., Joints in Building, Handbook of Concrete Engineering, New York, Van Nostrand Reinhold Company, 1974, pp. 94-110.
  28. Wood, R. H., "Joints in Sanitary Engineering Structures," Concrete International, Vol. 3, No. 4, 1981, pp. 53-66.

Cited by

  1. A Case Study on Cause Analysis for Longitudinal Crack of Duct Slab in Tunnel vol.16, pp.5, 2012, https://doi.org/10.11112/jksmi.2012.16.5.019
  2. A Study of Crack Shape Analysis based on Properties of Member in Apartment Exterior Wall vol.16, pp.3, 2015, https://doi.org/10.6106/KJCEM.2015.16.3.143