活性砂漿試體受單維電場作用下陽離子傳輸行為之研究; Cation Ion Migration Bhavior of Reactive Mortar Effected by 1D Electric Field ｗith Different Density.

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Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/1317

Title:	活性砂漿試體受單維電場作用下陽離子傳輸行為之研究;Cation Ion Migration Bhavior of Reactive Mortar Effected by 1D Electric Field ｗith Different Density.
Authors:	劉慧茹;Hui-ru Liu
Contributors:	土木工程研究所
Keywords:	鹼－矽反應;電化學;維修;ALMT;Repair;Mortar;Electrochemical;Alkali-silica reaction
Date:	2009-06-17
Issue Date:	2009-09-18 17:26:55 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	運用加速鋰離子傳輸技術(Accelerated Lithium Migration Technique, ALMT)維修ASR的策略，是利用電的趨動力移除會誘發ASR的Na+及K+的同時，送入對ASR有抑制效果的Li+。本研究施加定電壓及定電流電場進行ALMT試驗，分別以LiOH．H2O及飽和Ca(OH)2作為陽與陰極電解液，分析改變砂漿試體的水灰比、水泥含鹼量、粒料/水泥比、長度，以及通電歷時與電場強度，對Na+及K+移除與Li+送入試體的傳輸行為影響。結果顯示，施加定電壓時，阻抗會隨時間增加，發現電壓值並不適合作為控制離子傳輸指標；施加定電流密度時，發現電流密度與Li+、Na+及K+的穩態流量有良好線性關係，適合作為ALMT工程實務的通電模式。電場強度愈大、水灰比愈高、含鹼量愈低及粒料/水泥比愈高時，愈有利於離子傳輸。增加試體長度並不會改變Na+及K+移出與Li+送入試體的速率。當通電至試體內的Na+與K+移出完成時，試體的膨脹量可降低為未通電試體的71 %，若通電至Li+流量達穩態時，則可完全抑制ASR膨脹問題。 An Accelerated Lithium Migration Technique (ALMT) was applied to simultaneously drive alkali out and lithium into concrete as a remedy for alkali-silica reaction (ASR) problems. Constant voltages and current densities were applied during the ALMT testing process. The anolyte and catholyte solutions consisted of 1L 1N LiOH．H2O and saturated Ca(OH)2, respectively. This research altered the conditions of testing such as the w/c ratio, the alkali content of cement and the aggregate/cement ratio of mortars, the distance of electrodes and the time-span of testing to analyze the migration behaviors of cations. The results show that the system resistance increases during the testing and the voltage value is not suitable as an index of ionic migration. There is a good linear relationship between the applied current density and the steady flux of the Li+, Na+ or K+. It is beneficial for the migration of ions as the bigger the applied electrical field, the higher the water/cement ratio, the lower the alkali content of cement and the higher the aggregate/cement ratio. Increasing the distance of electrodes does not alter the migrating rate of Li+, Na+ and K+. When the alkali content of specimen is complete removal, the decrease in its ASR expansion is 71 percent. When the flux of Li+ reaches steady state, the ASR expansion is inhibiting completely.
Appears in Collections:	[Graduate Institute of Civil Engineering] Electronic Thesis & Dissertation

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