碱金属离子对废玻璃砂浆碱骨料反应的影响

Effect of Alkali Ions on Alkali-Silica Reaction in Waste Glass Incorporated Mortar

关键词:  废玻璃  砂浆  碱骨料反应  碱金属离子  微观结构

Key words:  waste glass  mortar  alkali-silica reaction  alkali ion  microstructure

摘要:

以废玻璃为骨料，NaOH和NaCl为碱金属离子来源，通过玻璃溶解及玻璃砂浆碱骨料反应（ASR），研究了碱金属离子对玻璃砂浆ASR的影响.结果表明：玻璃溶解速率随溶液中OH^—浓度增加而升高，当OH^—浓度为1.000 mol/L时达到峰值，随后降低；在NaOH环境中，ASR膨胀率随NaOH浓度升高而增加，膨胀速率随时间延长而递减；在NaCl环境中，膨胀主要发生在侵蚀初期；在NaOH与NaCl共存环境中，膨胀率与膨胀速率均明显增大，侵蚀后期膨胀速率增加显著；NaOH浓度的增加及NaCl的加入，均导致ASR凝胶钠硅比升高，增加了凝胶的吸水肿胀性，最终加剧膨胀.

Abstract:

Using waste glass as the aggregate， NaOH and NaCl as sources of alkali metal ions， the influence of alkali ions on alkali-silica reaction （ASR） in glass mortar was studied through the dissolution of glass and the reaction of alkali aggregate in glass mortar. The results show that the dissolution rate of glass increases with the increase of OH^— concentration in the solution， reaching a peak when the OH^— concentration is 1.000 mol/L， and then decreases. In NaOH environment， the expansion rate increases with the increase of NaOH concentration， and decreases with the passage of time. In NaCl environment， expansion mainly occurs in the early stages of erosion. In the coexisting environment of NaOH and NaCl， the expansion ratio and expansion speed both increase significantly， and the expansion rate increases noticeably in the later stages of erosion. The increase of NaOH concentration and the addition of NaCl both lead to an increase in the gel sodium-silica ratio in ASR gel， which increases the gel’s water absorption and swelling properties， ultimately exacerbating the expansion.