고유동 콘크리트의 사용이 일반화 되면서 유동화제 사용에 따른 콘크리트의 초기 재료물성 발현에 대한 관심이 높아지고 있다. 콘크리트 수화반응에 따른 응결시점은 초기 물성 발현을 나타낼 수 있는 지표 중 하나이며, 이러한 응결시점 평가를 위해 관입저항시험과 함께 다양한 비파괴 평가 기법들이 사용되고 있다. 본 연구에서는 전기비저항 측정법을 이용하여 유동화 모르타르의 응결 지연 현상 평가에 관한 실험연구를 수행하였다. PC계 유동화제 첨가량에 따른 총 9종류의 모르타르 샘플을 준비하였으며, 4-전극법을 이용한 초기재령 모르타르 샘플의 전기비저항 변화를 24h 측정하였다. 측정결과로부터 결정된 전기비저항 상승시기를 모르타르 응결시점 평가를 위한 전기적 변수로 사용하였으며, 측정결과의 비교 분석을 위해 동일 샘플의 관입저항시험을 실시하였다. 또한 유동화 모르타르의 1일 동 탄성계수 및 압축강도 측정을 통해 전기비저항 측정을 이용한 유동화 모르타르의 초기 재료물성 평가 가능성을 확인하였다.

In this study, Retarder, which shows characteristics of delay hydration reaction and reduce hydration heat in concrete, was processed through granulation and paraffin coat to induce reaction by hydration heat. The prepared paraffin coated granular retarder was mixed with the mortar and the setting time was measured according to the desired temperature. As a result, it was confirmed that paraffin coated granular retarder which does not react during the concrete placing exhibits performance depending on the temperature.

Be constructed in the Middle East, recent overseas plant business mainly due to an increase in the amount of concrete in the construction sector is growing. When using plain concrete and concrete development of the initial expansion of the initial hydration, due to thermal stress that causes cracks in the concrete problems, and prevention of this by the use of the delay is expected to increase. In addition to the increase in domestic traffic produced in ready-mixed concrete plants and concrete due to high temperature during transportation upon arrival at the scene quickly if condensation begins to degrade due to the slump loss and workability after curing of cold joint and cause filling defects and the need for the measures . In the case of the powder that is currently on the market in order to obtain a uniform delay effects can be mixed, may be added, such as, wet, etc. Keep a less efficient storage, even if the delay has to be taken. This powder improves the delay and store it in a tablet, a delay effect to encourage the development of tablet, and the delay for compliance with basic properties was investigated.