Journal of the Korean Recycled Construction Resources Institute (한국건설순환자원학회논문집)

Korean Recycled Construction Resources Institute (한국건설순환자원학회)
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Influence of Exposure Environmental Conditions on the Crack Healing Performance of Self-healing Repair Mortar Specimens

노출환경 조건이 자기치유형 보수 모르타르 시험체의 균열 치유성능에 미치는 영향

  • Lee, Woong-Jong (Self-healing Green Concrete Research Center, Sungkyunkwan University) ;
  • Lee, Hyun-Ho (Department of Civil, Architectural and Environmental System Engineering, Sungkyunkwan University) ;
  • Ahn, Sang-Wook (Intchem Co., Ltd.) ;
  • Lee, Kwang-Myong (Department of Civil, Architectural and Environmental System Engineering, Sungkyunkwan University)
  • 이웅종 (성균관대학교 자기치유 친환경 콘크리트 연구센터) ;
  • 이현호 (성균관대학교 건설환경시스템공학과) ;
  • 안상욱 ((주)인트켐) ;
  • 이광명 (성균관대학교 건설환경시스템공학과)
  • Received : 2018.10.08
  • Accepted : 2018.10.29
  • Published : 2018.12.30
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Abstract

Since the crack self-healing materials are activated according to the exposure environmental conditions from the time of crack occurrence, it is very important to clarify the relationship between the healing performance and the exposure environmental conditions of the crack surface. In this paper, the influence of the exposure environmental conditions on the crack healing performance of self-healing repair mortar was investigated through the water permeability test. The influence of temperature and humidity on the crack width of cracked specimens was evaluated. As a result of measuring the change of the crack width, the effect of curing temperature was negligible but it was confirmed that crack-closing occurred due to the change of dry-wet condition. The healing materials produced on the crack surface of the specimens was identified as calcite minerals. Since the minerals with high density are precipitated under the influence of gravity, the healing performance is somewhat different according to the direction of the crack surface, and the healing performance was significantly improved in the wet exposure condition than the air exposure condition.

균열 자기치유 소재는 균열발생 시점부터 노출환경 조건에 따라 활성화되기 때문에 치유성능과 균열면의 노출환경 조건과의 관계 규명이 매우 중요하다. 이에 본 연구에서는 자기치유형 보수 모르타르의 치유성능에 노출환경 조건이 미치는 영향을 투수시험을 통하여 조사하였다. 균열시험체의 초기 균열폭에 대한 온도 및 습도의 영향을 조사한 결과, 양생온도의 영향은 미미하였으나, 건습변화에 의해서는 균열닫힘 현상이 발생하고 있음을 확인하였다. 그리고 자기치유형 보수 모르타르 시험체의 균열부위에서 생성된 치유물질은 calcite 광물로 확인되었다. 밀도가 높은 calcite 광물은 중력의 영향을 받아 침강하기 때문에, 균열면의 방향에 따라 치유성능에 다소 차이를 나타냈으며, 또한 대기노출 조건보다 습윤노출 조건에서 치유성능이 크게 향상되었다.

Keywords

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Fig. 1. Direction of the crack surface of cracked specimens

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Fig. 2. Procedure for measurement of crack widths according to temperature change

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Fig. 3. Procedure for measurement of crack widths according to humidity change

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Fig. 4. Precipitation of healing products in cracked specimens

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Fig. 5. XRD analysis results of healing product in cracked specimen

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Fig. 6. The results of water permeability test

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Fig. 7. Comparison results of specimens with similar initial water flow rate

Table 1. Mix proportion of self-healing repair mortar

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Table 2. Cracking time and exposure conditions of the crack surface for water permeability test specimens

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Table 3. Flow and compressive strength of self-healing repair mortar

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Table 4. Measurement results of crack widths at each temperature of cracked specimen

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Table 5. Measurement results of crack widths according to exposure conditions of cracked specmen

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Table 6. Change in reduction rate of water flow with healing duration after cracking 28 days

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References

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