以離子傳輸觀點探討加速鋰離子傳輸技術之有效電極間距

Discuss the Effective Electrode Distance of Accelerated Lithium Migration Technique from the Viewpoint of Ion Migration

王韡蒨(Wei-Chien Wang) ； 李釗(Chau Lee) ； 劉志堅(Chih-Chien Liu) ； 蔡欣妤(Hsin-Yu Tsai) ； 游雁斐(Yen-Fei Yu)

《中國土木水利工程學刊》 26卷3期 (2014/09) Pp. 229-234

https://doi.org/10.6652/JoCICHE.201409_26(3).0007

摘要

加速鋰離子傳輸技術（ALMT）是發展用於抑制混凝土的鹼-矽反應（ASR）問題，當施加定電壓時，離子傳輸的速率會受到混凝土結構及電極間距影響，本研究對三種不同水灰比混凝土施加60V定電壓，使用不同試體長度以調整電極間距分別為8、16、24、32及38cm，進行ALMT試驗，過程中監測陰極電解液內的鋰、鈉及鉀離子濃度，通電結束時間以鹼質不再明顯移出或電流密度降到1A/m^2加以決定，藉建立離子濃度與累積電荷量關係，評估離子傳輸效能，以分析電極間距對ALMT離子傳輸的影響。試驗結果顯示，混凝土水灰比愈大，愈有利於離子傳輸。初始電流會隨電極間距增加而降低，離子傳輸效能減少。當水灰比為0.48、0.58及0.68時，電極間距分別在16、24及32cm以下，有較佳的離子傳輸效能，且可移出混凝土所含含鹼量達80%以上，送入足夠的鋰離子，因此，針對不同水灰比，上述電極間距可作為ALMT實務應用時的有效上限。

關鍵字

加速鋰離子傳輸技術 ； 鹼－矽反應 ； 電極間距 ； 混凝土

並列摘要

The development of Accelerated Lithium Migration Technique (ALMT) is used to inhibit the alkali-silica reaction (ASR) problem of concrete. When apply constant voltage, the migration rate of ions is affected by the structure of concrete and the electrode distance of ALMT. This research uses the constant voltage of 60V on three kinds of w/c ratio concrete. Using different specimen lengths adjust the distance between electrodes of ALMT to be 8,16,24,32 and 38cm. Monitor the concentrations of the lithium, sodium and potassium ions in catholyte during the ALMT processing. The ALMT test stop when the removed alkalis from concrete no more increase apparently or the applied current density of ALMT lower than 1A/m^2. Evaluate the migration efficiency by establishing relations between ion concentration and the cumulative amount of charge to analyze the effect of the electrode distance on the migration behavior of ions. Results show that the higher w/c ratio of concrete is beneficial to the migration of ions. The initial current decreases with the electrode distance increases, and the migration efficiency of ions will reduce. For concrete with the w/c ratios of 0.48, 0.58 and 0.68, the electrode distance lower than 16, 24 and 32 cm, respectively, have the better migration efficiency of ions, remove alkalis from concrete more than 80% and drive enough lithium ion into concrete. Therefore, for concrete with different w/c ratio, the above electrode distances can be the upper limit of applied electrical field under the practical ALMT application.

並列關鍵字

Accelerated Lithium Migration Technique ； alkali-silica reaction ； electrode distance ； concrete