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Title |
Electromechanical Properties of Smart Repair Materials based on Rapid Setting Cement Including Fine Steel Slag Aggregates
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Authors |
김태욱(Tae-Uk Kim) ; 김민경(Min-Kyoung Kim) ; 김동주(Dong-Joo Kim) |
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DOI |
https://doi.org/10.11112/jksmi.2023.27.4.62 |
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Keywords |
자가감지 콘크리트; 급속 보수재료; 전도성 기능성 재료; 손상 감지; 응력 감지 Self-sensing concrete; Repid repair material; Conductive functional filler; Damage sensing; Stress sensing |
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Abstract |
This study investigated the electromechanical properties of cement based smart repair materials (SRMs) according to the different amounts of fine steel slag aggregates (FSSAs). SRMs can self-diagnose the quality of repairing and self-sense the damage of repaired zone. The replacement ratios of FSSAs to sand for SRMs were 0% (FSSA00), 25% (FSSA25), and 50% (FSSA50) by sand weight. The electrical resistivity of SRMs generally decreased as the compressive stress of SRMs increased: the electrical resistivity of FSSA25 at the age of 7 hours decreased from 78.16 to 63.68 kΩ-cm as the compressive stress increased from 0 to 22.37 MPa. As the replacement ratio of FSSAs by weight of sand increased from 0% to 25%, the stress sensitivity coefficient (SSC) of SRM at the age of 7 h increased from 0.471 to 0.828 %/MPa owing to the increased number of partially conductive paths in the SRMs. However, as the replacement ratio of FSSAs further increased up to 50%, the SSC decreased from 0.828 to 0.649 %/MPa because some of the partially conductive paths changed to continued conductive ones. SRMs are expected to self-sense the quality and future damage of repaired zone only by measuring the electrical resistivity of the repaired zone in addition to fast recovery in the mechanical resistance of structures.
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