한랭조건하 배합강도 결정시 혼합시멘트 사용 콘크리트의 강도 보정 제안

The objective of the paper is to propose the correction factors of the concrete using blended cement at the stage of designing specified strength under low temperature environment. Strength development of the concretes using blended cements are estimated applying equivalent age methods. Ordinary Portland cement(OPC), fly ash cement(FAC), blast furnace slag cement(BSC) and ternary blended cement with FA and BS are used for the binders. Compressive strengths are measured using the concretes cured at 5, 20 and 35℃. Test results indicated that the use of blended cement led to decrease in strength development at 5℃ at early age. Strength correction factors with each level of age and binder types were suggested with 3 MPa levels. OPC, FAC and ternary blended cement had 3 MPa of strength correction factors for 28 days and 42 days of strength management period, while there are no need at 56 days and 91 days. BSC concrete had 3~6 MPa of strength correction factors from 28 days to 42 days. Within the scope of this study, strength correction factors should be added to Korea Construction Standard to secure design strength of the structural concrete cured at low temperature.