Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
권호 표지
DOI QR코드

DOI QR Code

The Evaluation of Durability Performance in Mortar Curbs Containing Activated Hwangtoh

활성 황토를 혼입한 모르타르 기반 경계석의 내구성능 평가

  • Kwon, Seung-Jun (Department of Civil and Environmental Engineering, Hannam University) ;
  • Kim, Hyeok-Jung (Industry Academic Cooperation Foundation, Hankyong National University) ;
  • Yoon, Yong-Sik (Department of Civil and Environmental Engineering, Hannam University)
  • 권성준 (한남대학교 토목환경공학과) ;
  • 김혁중 (한경대학교 산학협력단) ;
  • 윤용식 (한남대학교 건설시스템공학과)
  • Received : 2020.11.03
  • Accepted : 2020.12.08
  • Published : 2020.12.30
Download PDF
⟨ Previous Next ⟩

Abstract

Hwangtoh is the rich resource that accounts for about 15.0% of the domestic soil, and can be used as the admixture of concrete with Pozzolan characteristics if activated by rapidly freezing after burning with high temperature. In this study, the mortar curbs containing active hwangtoh were produced, based on the mixture for the mortar curbs sold on the market. The substitution rate of active hwangtoh were considered 10.0% and 25.0%, and the test items were selected to compressive and flexural strength tests, freezing/thawing resistance tests, accelerated carbonation tests, and accelerated chloride diffusion tests. In the results of the mechanical performance, it was showed that the highest strength was evaluated in OPC mixture, and the increase in strength was small by the increase of age, which was believed to be due to the fact that most of the strength in each mixture was created in three days of steam curing. The results of the freezing/thawing tests for 28 aged days showed the reduction rate of compressive strength was 85.0% or higher for all specimen, meeting the criteria presented. The accelerated carbonation tests were carried out on the specimen at 28 days of age, and the results showed that the mortar with active hwangtoh had lower carbonation resistance performance than mortar with OPC. The passed charge of each mixture was assessed in accordance with ASTM C 1202 on 28 and 91 aged days. The OPC mixture had "Low" rate and the mortar with active hwangtoh had "Moderate" rate. So it was thought that the mortar with active hwangtoh had appropriate resistance performance for chloride attack.

황토는 국내 토양의 약 15.0%를 차지하는 풍부한 자원이며, 고온소성 후 급랭하여 활성화시키면 포졸란 특성을 갖는 콘크리트 결합재로서 사용할 수 있다. 본 연구에서는 시중에서 판매되는 경계석 배합을 기반으로 하여 활성 황토 혼입 모르타르 경계석 시편을 제작하였다. 활성 황토의 혼입율은 10.0% 및 25.0%를 고려하였으며, 시험 항목으로는 압축 및 휨 강도 시험, 동결융해 저항 성능 평가, 촉진 탄산화 시험, 촉진 염화물 확산 시험을 설정하였다. 역학적 성능 평가 결과 OPC 배합에서 가장 높은 강도가 평가되었으며, 재령일의 증가에 따른 강도 증가가 적게 나타났는데 이는 3일간 증기 양생을 통해 대부분의 강도가 발현되었기 때문으로 사료된다. 재령 28일에 해당하는 시편을 대상으로 동결융해 저항성능 평가 결과, 모든 배합에서 85.0% 이상의 강도 저하율을 나타내어 제시된 기준에 만족하였다. 촉진 탄산화 시험은 재령 28일 시편을 대상으로 수행되었으며 활성 황토 혼입 배합에서 OPC 배합 대비 다소 저하된 탄산화 저항성능을 나타내었다. 재령 28일 및 91일에 ASTM C 1202에 준하여 각 배합의 통과 전하량을 평가하였다. OPC 배합의 경우 "Low" 등급을, 활성 황토 혼입 배합의 경우 "Moderate" 등급을 나타내어 활성 황토 혼입 배합에서도 적절한 염해 저항성능을 나타내는 것으로 보인다.

Keywords

References

  1. Choi, H.Y., Hwang, H.Z., Kim, M.H., Kim, M.H. (2000). A study on the development of hwangtoh admixture for the application of cement mortar, Journal of the Architectural Institute of Korea - Structure & Construction, 16(6), 95-102 [in Korean].
  2. Choi, H.Y., Kim, M.H., Kim, M.H., Hwang, H.Z., Choi, S.W. (2001). Experimental study on the properties of concrete by the kinds of admixture and the replacement ratios of activated hwangtoh, Journal of the Korea Concrete Institute, 13(2), 123-129 [in Korean]. https://doi.org/10.22636/JKCI.2001.13.2.123
  3. Go, S.S., Lee, H.C., Lee, J.Y., Kim, J.K., Chung, C.W. (2009). Experimental investigation of mortars using activated hwangtoh, Construction and Building Materials, 23(3), 1438-1445. https://doi.org/10.1016/j.conbuildmat.2008.07.007
  4. Hwang, H.Z., Roh, T.H., Kim, J.I. (2008). Characteristics of strength and durability of hwangto-concrete according to its mixing condition, KIEAE Journal, 8(5), 55-60 [in Korean].
  5. Hwang, S.H., Yoon, Y.S., Kwon, S.J. (2019). Carbonation behavior of GGBFS concrete considering loading conditions and cold joint, Journal of the Korea Concrete Institute, 31(4), 365-373 [in Korean]. https://doi.org/10.4334/jkci.2019.31.4.365
  6. Kang, S.S., Lee, S.L., Hwang, H.Z., Cho, M.C. (2008). Hydration heat and shrinkage of concrete using hwangtoh binder, Journal of the Korea Concrete Institute, 20(5), 549-555 [in Korean]. https://doi.org/10.4334/JKCI.2008.20.5.549
  7. Kim, S.B., Yi, N.H., Kim, H.Y., Phan, D.H., Kim, J.H. (2008). "Flexural behavior of reinforced concrete beams mixed with hwang-toh," Proceedings of the Korea Concrete Institute Conference, Korea Concrete Institute, Seoul, Korea, 281-284 [in Korean].
  8. Kwon, S.J. (2017). Probability-based LCCO2 evaluation for underground structure with repairing timings exposed to carbonation, Journal of the Korean Recycled Construction Resources Institute, 5(3), 239-246 [in Korean]. https://doi.org/10.14190/JRCR.2017.5.3.239
  9. Kwon, S.O., Bae, S.H., Lee, H.J., Jung, S.H. (2014). Characteristics for reinforcement corrosion and chloride ion diffusion of high volume fly ash concrete, Journal of the Korean Recycled Construction Resources Institute, 2(1), 34-39 [in Korean]. https://doi.org/10.14190/JRCR.2014.2.1.034
  10. Lee, N.K., Park, H.G., Hwang, H.Z. (2010). Shear and bond strength of activated hwangtoh concrete beam, Journal of the Korea Concrete Institute, 22(5), 685-694 [in Korean]. https://doi.org/10.4334/JKCI.2010.22.5.685
  11. Metha, P.K., Monteiro, P.M. (2009). Concrete-Structure, Properties, and Materials, 2nd Edition, Prentice Hall, New-Jersey, 113-178.
  12. Oh, K.S., Moon, J.M., Park, K.T., Kwon, S.J. (2016). Evaluation of load capacity reduction in RC beam with corroded FRP hybrid bar and steel, Journal of the Korea Institute for Structural Maintenance and Inspection, 20(2), 10-17 [In Korean]. https://doi.org/10.11112/jksmi.2016.20.2.010
  13. Yang, H.M., Lee, H.S., Yang, K.H., Ismail, M.A., Kwon, S.J. (2018). Time and cold joint effect on chloride diffusion in concrete containing GGBFS under various loading conditions, Construction and Building Materials, 167(2018), 739-748. https://doi.org/10.1016/j.conbuildmat.2018.02.093
  14. Yoon, Y.S., Kwon, S.J. (2019). Evaluation of apparent chloride diffusion coefficient and surface chloride contents of FA concrete exposed splash zone considering crack width, Journal of the Korea Institute for Structural Maintenance and Inspection, 23(6) 18-25 [in Korean].
  15. Yoon, Y.S., Ryu, H.S., Lim, H.S., Koh, K.T., Kim, J.S., Kwon, S.J. (2018). Effect of grout conditions and tendon location on corrosion pattern in PS tendon in grout, Construction and Building Materials, 186(2018), 1005-1015. https://doi.org/10.1016/j.conbuildmat.2018.08.023