양생 온도에 따른 모르타르 내의 염소이온에 의한 철근 부식 거동 특성에 관한 연구 Part 2: 염소이온에 의한 철근 부식

초록

In this study, the influence of curing temperature on behaviour of steel corrosion was investigated at 4, 20 and 50 °C for 28 days of curing. There were two different types of corrosion schemes: (1) external corrosion with chloride solution consisting of 4.0M NaCl solution and (2) internal corrosion with chloride in cast. As a result, it was found that an increase in the curing temperature resulted in an increase in the time to corrosion, because the hydration at the higher temperature could provide high alkalinity of the pore solution, resistance to a pH fall and lower porosity , leading to the passivity of steel. Also, the GGBS indicated the longer time to corrosion, compared to OPC, due to the even lower diffusivity of chloride ions with lower chloride threshold and higher surface chloride. In internal chloride corrosion, an increase in the curing temperature resulted in an increase in the corrosion resistance. Also, OPC had the higher corrosion resistance to GGBS, but the rate of corrosion propagation for GGBS was quite lower for GGBS, presumably due to the lower cathodic reaction, resulting from the lower porosity.

키워드