| 摘要: | 本研究利用先前研究團隊所使用配比HIC-C與HIC-M及配比C與配比M的數據基礎下，量測更長時間之試驗數據，以利得到更精確之推估結果。配比HIC-C、HIC-M為2010年依據AASHTO T260所改良之長期浸泡試驗法，目前已完成五年之數據。另外配比C與配比M為2014年依照ASTM C1556之試驗方法。最後，將比較長期浸泡及ASTM兩種方式之試驗方法及其試驗結果。
依據以上結果，本研究期望再尋求新方法能讓混凝土耐用度提高，於本研究利用不同養護溫度60℃(1、2、4天)及80℃(3、4、3+200℃烘箱12小時)，觀察是否能提升混凝土之耐久性，達到提高品質之效果，分別進行抗壓強度試驗、孔隙率試驗、孔隙粒徑分布與電阻率試驗，評估不同養護方式與養護齡期之影響。
結果顯示長期浸泡試驗將隨浸泡時間越長氯離子含量越高，而ASTM C1556的方法因為混凝土隨著齡期增加水化程度上升，使得氯離子入侵困難，瞬時擴散係數隨齡期增加而降低，故混凝土受氯離子入侵的服務年限推估，將建議使用ASTM C1556方法，此法能模擬隨時間增加而擴散係數降低的特性。於孔隙率、孔隙分佈、電阻率等，相較於常溫養護使用80℃高溫熱水養護能有效提升品質，使孔隙更緻密，可影響氯離子入侵之能力，而試驗成果最佳高溫養護天數為4天。
;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 five 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.
From the test results, more cholride ions penetrated into concrete after long immersion duration. But, with ASTM C1556 test method, the aging concrete will get higher hydration degree, and caused the chloride ions hard to penetrate into concrete body, and lower down the instant diffusion coefficient. Therefore, under the effectiveness of chloride ions penetrations, ASTM C1556 test method is recommended for concrete service life calcuations. This method can simulate the characteristic of diffusion coefficient decreased whenever ageing time increased.
By comparing with room temperature maintenance method, the best curing method was found to be 80℃ high temperature hot water curing for 4 days; with which, it can effectively increase the concrete quality and service life by decreasing porosity and resisting chloride ions′ diffusions. |
