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The barriers of facilities which dispose wastes with low radioactivity are mainly composed of concrete. But unlike the normal purpose of concrete, the barrier concrete is expected to be used for more than several hundred years.This study measures long-period experimental data to get better estimated results based on previous studies by using mixes HIC-C and HIC-M, and mixes C and M. Mixes HIC-C and HIC-M were prepared and revised from AASHTO T260 test method in 2010. So far, the experiments have been ongoing and data collected for six years. On the other hand, in 2014, mixes C and M were made according to ASTM C1556 test method. Finally, the study will make comparisons of long-period immersion method and ASTM method based on experimental procedures and test results.
Based on above data and results, this study expects to seek for new methods to extend and increase concrete′s durability. In this study, under different curing conditions at high temperatures of 60℃ (1、2、4 days) and 80℃ (3 days、4 days、3 days + 200℃ oven-dry 12 hours), to observe whether the concrete quality and durability will be improved. There are some tests used for this study to evaluate the effects of maintenance methods and maintenance period, including compressive strength test, porosity test, pore size distribution and resistivity test. Fibre distribution characteristics were evaluated to investigate their effect on the quality. For this purpose, an image processing technique developed in this study was employed.
From the test results, the aging concrete will get higher hydration degree, and caused the chloride ions hard to penetrate into concrete body. Therefore, under the effectiveness of chloride ions penetrations, ASTM C1556 test method is recommended for concrete service life calcuations. | en_US |