| 摘要: | 本研究探討三項主題：(1) Li＋、Na＋及K＋與活性粒料粉體的反應行為、(2) Li＋、Na＋及K＋與水泥水化產物的結合行為、及(3) Li＋取代已結合於水泥水化產物或鹼矽膠體內之Na＋及K＋行為，以分析Li＋抑制鹼－矽反應的機理。試驗粒料包括東河變質砂岩、Pyrex玻璃及矽砂，使用的鹼金屬化合物包括NaOH、KOH、LiOH．H2O及LiNO3。結果顯示，在Li＋、Na＋及K＋與活性粉體反應研究方面，發現活性粉體浸泡含Na＋及K＋溶液時，浸泡時間增加，SiO2的溶出量、OH－的減少量及Na＋、K＋的減少量均會增加；但浸泡於含Li＋溶液時，與浸泡含Na+及K+溶液比較，發現OH－減少量較多，SiO2溶出量低很多，而Li＋的減少量較高，顯示Li化合物會直接與粒料中的活性矽反應，生成溶解度較低、不會吸水膨脹的物質。在Li＋、Na＋及K＋與水泥水化結合研究方面，發現結合於水化產物的比例為Li＋>Na＋>K＋，顯示實務上添加鋰化合物以抑制ASR膨脹時，需足量添加，否則可能會造成更大的膨脹，而添加LiNO3的結合比例會大於添加LiOH．H2O。在Li＋取代結合於水泥水化產物內之Na＋及K＋能力研究方面，發現LiNO3較LiOH．H2O取代能力為佳，此外，Li＋濃度愈高、浸泡時間愈久，則取代量愈多，顯示實務上已噴灑或浸泡的方法維修受ASR影響的構造物，可能會有效，但所需時間及效果仍待評估。 There are three primary objectives in this research. The first is to evaluate the affect of reaction of Li＋, Na＋, K＋ to reactive aggregate powder. Second is to determine the combination of Li＋, Na＋, K＋ in hydration product. The third is to evaluate the suppression function by assessing the reactivity in the utilization of lithium ion as a replacement in cment hydration products combination or ASR gel. The materials used for the experiments are Ton-River aggregate, Pyrex glass and silica. In addition, alkali composition used include NaOH, KOH, LiOH. H2O and LiNO3. The result shows that reaction of Li＋, Na＋, K＋ affects the reactive powder. The immersion of reactive aggregate in Na＋, K＋ will give added timing which will cause the dissolution of silica content, drop of hydroxil ions and an increase in Na＋, K＋. However, when immersed in Li＋ liquid, the reduction of hydroxyl ions will increase and dissolution of silica content will be lower. The dramatic reduction due to Li＋ prove that Li＋reactivon to the reactive aggregate are more direct. Its lower dissolution prevented the swelling of the material. Regarding the Li＋, Na＋, K＋ combination of hydrationn products, the research discover that the proportion of the hydration product are Li＋> Na＋> K＋. The implication of this is that the quantity of the admixture should be adequate to prevent the ASR from swelling while Li composition is added. The combination of LiNO3 proportion shall be greater than LiOH.H2O. With regards to the reactivity in the utilization of Li＋ in replacing the cement hydration product combination, it is discovered that the capacity of replacement by LiNO3 is better than LiOH.H2O. In addition, the increase in Li＋ concentration and the increase in the duration of immersed time will increase the replacement. This implies that the spray or immersion approach is good for correction of structure damaged by ASR. However further evaluation requires more time. |
