In this paper, a comparative cold weather concrete member test was conducted with gang form and euro form, which are generally used as forms for construction in Korea. Three members were fabricated for the comparative test: the member with the general gang form and euro form, the member with the existing insulation gang form on the outside and the general form on the inside, and the member with the existing insulation gang form on the outside and the newly developed insulation euro form on the inside. In this test, ready-mixed concrete with a nominal strength of 24 MPa that met a certain standard was cast in the cold weather concrete condition at a temperature of 0℃ (5℃ ～–5℃), which is lower than the cold weather concrete management standard temperature in Korea 4℃ mean daily temperature. The standard water curing compressive strength, core compressive strength and temperature history were measured and comparatively examined for the general gang form-general euro form and insulation gang form-general euro form members that were cured at a certain inside temperature, and for the insulation gang form-insulation euro form member that was cured without additional temperature control.

This study is analyzing a member kind after placing concrete, the location-based temperature record, and the strength development, by making insulation gang-form with application of polyurethane form to general gang-form for securing efficient concrete quality in the condition of cold weather. According to our experimental results, the member of general gang-form with curing in the same condition as the actual field didn’t drop to under 3˚C until before 24 hours in the early part, but fell to under 0˚c from 36 hours later because a large rise in temperature caused by hydration reaction didn't occur. On the other hand, in case of insulation gang-form, the temperature on the surface and the central part didn't go down to under 3˚C before 12 hours in the early part and didn't fall to under it even until 72 hours after it while the peak temperature went up to 12˚C. Thus, it could be known to definitely have excellent insulation effect compared to space heating curing, which is generally performed on the spot. In comparison with space heating curing whose error in curing temperature is big every field, it is judged to likely have great effect on improvement in concrete quality given the work construction in cold weather and on early demolding in a cast during winter.

본 연구에서는 외기온 영하조건에서 노출시간 변화별 콘크리트의 초기동해 피해를 입는 온도이력을 확인하고, 실험연구결과 –10℃인 외기조건에서 200 mm 두께의 슬래브는 18시간까지는 외기온에 노출되어도 콘크리트의 수화열에 의해 초기동해 피해가 발생하지 않는 것을 알 수 있었다.

In this study, we analyzed the effect of heating curing on apartment construction in clod weather frame construction. The temperature was measured using a temperature sensor in winter and in non-winter season, the temperayure difference in the winter concrete temperature history was more than 10 degrees.

This paper reviewed on the minimum strength of concrete in cold climates from the viewpoint of durability. The results show that the minimum strength to prevent early frost damage recommend to 21 MPa.