| URN | etd-0727109-235416 | Statistics | This thesis had been viewed 853 times. Download 21 times. |
| Author | Ying-Pei Tsai | ||
| Author's Email Address | No Public. | ||
| Department | hazards | ||
| Year | 2008 | Semester | 2 |
| Degree | Master | Type of Document | Master's Thesis |
| Language | zh-TW.Big5 Chinese | Page Count | 196 |
| Title | Study of Chloride Diffusion Behavior and Service Life Prediction of Recycled Concrete of Taiwan | ||
| Keyword | |||
| Abstract | This research mainly studies the engineering properties of N-class recycled coarse aggregates and recycled concrete following the regulation specified in the ¡§Draft of Construction Specification for Recycled Concrete¡¨ published by the Ministry of Interior. The recycled concrete specimens are exposed to chloride solution as ASTM C1543 (Ponding test) to simulate the concrete specimens are exposed to marine environment. The total and the free chloride diffusion coefficients of the recycled concrete specimens were calculated by Fick¡¦s 2nd law. There are 8 different mixture proportions of recycled concrete specimens for the Ponding test which include two W/B ratios of 0.45 and 0.50, and three different proportions of recycled coarse aggregates (10%, 30%, 50%) to replace natural coarse aggregates by 91 days and 182 days immersion. The experimental results showed that the compressive strength of recycled concrete is increasing by the W/B ratio is decreasing, and the compressive strength of recycled concrete also is increasing by the ratio of replace of recycled coarse aggregate is decreasing. The 28 days compression strength of the 8 different proportion groups are during 27.5~43.35 MPa, and all of them reach the compression strength of B grade recycled concrete which is stipulated by the regulation of the ¡§Draft of Construction Specification for Recycled Concrete¡¨. For different water-binder ratio, the total chloride concentration of specimens of W/B=0.55 are about 1.3 times of those of W/B=0.45. And the free chloride concentration of specimens of W/B=0.55 are about 1.4 times of those of W/B=0.45. The chloride concentration of specimens with high water-binder ratio are higher than those of low water-binder ratio, the total chloride concentration in concrete is about 1.06~1.27 times of those of the free ones. The immersion time increasing, the chloride diffusivity reducing, the total chloride diffusion coefficients are about 1.04~1.8 times of those of the free chloride diffusion coefficients in the recycled concrete specimens. In this study, we calculate the service life time of the recycled concrete specimens by the LightCon model. The service life values of calculation result are not stable, and some groups are unable to calculate the life time correctly. The reason may be inferred that the two inspection time of 91 days and 182 days are too close to distinguish the different of the diffusivity of two specimens, and the chloride diffusion coefficients are too close to get a reasonable results. But we still expect an accurate service life prediction results by the continuing test of our study group. |
||
| Advisor Committee | |||
| Files | indicate access worldwide | ||
| Date of Defense | 2009-07-24 | Date of Submission | 2009-07-28 |