nono

• Main Authors: Yan-hua Mou, 牟妍樺
• Other Authors: Wei-hsing Huang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/08329554272816222983

碩士 === 國立中央大學 === 土木工程學系 === 101 === The barriers of facilities which dispose wastes with low radioactivity are mainly composed of concrete, but unlike the normal purpose of concrete, it should be used for more than several hundred years. However, due to Taiwan’s geographic feature- island, the sites of such facilities are mostly placed in marine environment, which will cause immense influences on the degradation and durability of concrete over a long period of time. This research aims on studying the degradation level of concrete while percolated by chloride ions, through using diffusion coefficient and threshold chloride concentration in empirical formulas, along with doing relative tests and analyses with HIC, ACI, to predict the time when reinforcing steel starts to be corroded. Establish the reliable analysis model of the service life for the propagation time of the reinforcement in concrete. The higher time-dependent hydration, the lower diffusion coefficient is. As the time is long, the value of diffusion coefficient is more stable. Predicting the time factor by using longer time can get the smaller variability and the greater accuracy. It needs the diffusion coefficient of chloride ions and the covered thickness of reinforcement to predict the propagation time of reinforcement in concrete. By diffusion of chloride, the service life of ACI assumed as 300 years is less than HIC.